Search for light scalar dark matter with atomic gravitational wave detectors
Arvanitaki, Asimina; Graham, Peter W.; Hogan, Jason M.; Rajendran, Surjeet; Van Tilburg, Ken
2016-01-01
We show that gravitational wave detectors based on a type of atom interferometry are sensitive to ultralight scalar dark matter. Such dark matter can cause temporal oscillations in fundamental constants with a frequency set by the dark matter mass, and amplitude determined by the local dark matter density. The result is a modulation of atomic transition energies. This signal is ideally suited to a type of gravitational wave detector that compares two spatially separated atom interferometers r...
Search for light scalar dark matter with atomic gravitational wave detectors
Arvanitaki, Asimina; Hogan, Jason M; Rajendran, Surjeet; Van Tilburg, Ken
2016-01-01
We show that gravitational wave detectors based on a type of atom interferometry are sensitive to ultralight scalar dark matter. Such dark matter can cause temporal oscillations in fundamental constants with a frequency set by the dark matter mass, and amplitude determined by the local dark matter density. The result is a modulation of atomic transition energies. This signal is ideally suited to a type of gravitational wave detector that compares two spatially separated atom interferometers referenced by a common laser. Such a detector can improve on current searches for electron-mass or electric-charge modulus dark matter by up to 10 orders of magnitude in coupling, in a frequency band complementary to that of other proposals. It demonstrates that this class of atomic sensors is qualitatively different from other gravitational wave detectors, including those based on laser interferometry. By using atomic-clock-like interferometers, laser noise is mitigated with only a single baseline. These atomic sensors ca...
Matter-wave beam splitter on an atom chip for a portable atom-interferometer
Kim, S J; Gang, S T; Kim, J B
2016-01-01
We construct a matter-wave beam splitter using 87Rb Bose-Einstein condensate on an atom chip. Through the use of radio-frequency-induced double-well potentials, we were able to split a BEC into two clouds separated by distances ranging from 2.8 {\\mu}m to 57 {\\mu}m. Interference between these two freely expanding BECs has been observed. By varying the rf-field amplitude, frequency, or polarization, we investigate behaviors of the beam-splitter. From the perspective of practical use, our BEC manipulation system is suitable for application to interferometry since it is compact and the repetition rate is high due to the anodic bonded atom chip on the vacuum cell. The portable system occupies a volume of 0.5 m3 and operates at a repetition rate as high as ~0.2 Hz.
Bound States of Guided Matter Waves: An Atom and a Charged Wire
Hau, Lene Vestergaard; Burns, Michael M.; Golovchenko, Jene A.
1992-01-01
We argue that it is possible to bind a neutral atom in stable orbits around a wire charged by a time-varying sinusoidal voltage. Both classical and quantum-mechanical theories for this system are discussed, and a unified approach to the Kapitza picture of effective potentials associated with high-frequency fields is presented. It appears that cavities and waveguides for neutral-atomic-matter waves may be fashioned from these considerations.
Measuring the Gouy Phase of Matter Waves using Singular Atom Optics with Spinor BECs
Schultz, Justin T.; Hansen, Azure; Murphree, Joseph D.; Jayaseelan, Maitreyi; Bigelow, Nicholas P.
2016-05-01
The Gouy phase is a propagation-dependent geometric phase found in confined waves as they propagate through a focus. Although it has been observed and studied extensively both in scalar and vector optical beams as well as in electron vortex beams, it has not yet been directly observed in ultracold matter waves. The Schrödinger equation has the same form as the paraxial wave equation from electromagnetism; expansion of a BEC upon release from a trap has the same mathematical form as a beam propagating away from a focus. We employ and extend this analogy between coherent optical beams and coherent matter waves to include spin angular momentum (polarization), which enables us measure the matter wave Gouy phase using coreless vortex spin textures in spinor BECs. Because the Gouy phase is dependent on the orbital angular momentum of the wave, the vortex and core states acquire different Gouy phase shifts. Parameters that are sensitive to the relative phase such as two-dimensional maps of the Stokes parameters rotate during evolution due to this phase difference. Using atom-optic polarimetry we can access the evolution of the atomic Stokes parameters and observe this rotation.
From quantum turbulence to statistical atom optics: new perspectives in speckle matter wave
Tavares, P E S; Telles, G D; Impens, F; Kaiser, R; Bagnato, V S
2016-01-01
Quantum Turbulence, the chaotic configuration of tangled quantized vortex lines, can be analyzed from the matter wave perspective in instead of the traditional fluid perspective. We report the observation of a remarkable similarity in between the dynamics of a freely expanding turbulent Bose-Einstein condensate and the propagation of an optical speckle pattern. Both follow very similar basic propagation characteristics. The second-order correlation is calculated and the typical correlation length of the two phenomena is used to substantiate the observations. The analogy between an expanding turbulent atomic condensate and a traveling optical speckle creates exciting prospects to investigate disordered quantum matter including the possibilities of a 3D speckle matter field.
Controllable Asymmetric Matter-wave Beam Splitter and Ring Potential on an Atom Chip
Kim, S J; Gang, S T; Anderson, D; Kim, J B
2015-01-01
We have constructed an asymmetric matter-wave beam splitter and a ring potential on an atom chip with Bose-Einstein condensates using radio-frequency dressing. By applying rf-field parallel to the quantization axis in the vicinity of the static trap minima added to perpendicular rf-fields, versatile controllability on the potentials is realized. Asymmetry of the rf-induced double well is manipulated without discernible displacement of the each well along horizontal and vertical direction. Formation of an isotropic ring potential on an atom chip is achieved by compensating the gradient due to gravity and inhomogeneous coupling strength. In addition, position and rotation velocity of a BEC along the ring geometry are controlled by the relative phase and the frequency difference between the rf-fields, respectively.
High momentum splitting of matter-waves by an atom chip field gradient beam-splitter
Machluf, Shimon; Folman, Ron
2012-01-01
The splitting of matter-waves into superposition states is a fundamental tool for studying the basic tenets of quantum behavior, as well as a building block for numerous technological applications. We report on the first realization of a beam-splitter by a combination of magnetic field gradients and a radio-frequency technique. It may be used for freely propagating or trapped atoms in a Bose-Einstein condensate or a thermal state. It has the advantageous feature of endowing its superposition state with a large differential momentum in the direction parallel or transverse to the atoms' motion, thereby, for example enabling to open large angles. As large space-time area of an interferometer increases its sensitivity, this may be used for new kinds of interferometry experiments (e.g. large angle Sagnac interferometry). Furthermore, it is also simple to use, fast, and does not require light.
Single spontaneous photon as a coherent beamsplitter for an atomic matter-wave
Energy Technology Data Exchange (ETDEWEB)
Tomkovič, Jiří; Welte, Joachim; Oberthaler, Markus K. [Kirchhoff-Institut für Physik, Universität Heidelberg, Heidelberg (Germany); Schreiber, Michael [Ludwig-Maximilians-Universität, München (Germany); Kiffner, Martin [Physik Department I, Technische Universität München, Garching (Germany); Schmiedmayer, Jörg [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Vienna (Austria)
2014-12-04
In free space the spontaneous emission of a single photon destroys motional coherence. Close to a mirror surface the reflection erases the which-path information and the single emitted photon can be regarded as a coherent beam splitter for an atomic matter-wavewhich can be verified by atom interferometry. Our experiment is a realization of the recoiling slit Gedanken experiment by Einstein.
Yao, Yu-Qin; Li, Ji; Han, Wei; Wang, Deng-Shan; Liu, Wu-Ming
2016-01-01
The intrinsic nonlinearity is the most remarkable characteristic of the Bose-Einstein condensates (BECs) systems. Many studies have been done on atomic BECs with time- and space- modulated nonlinearities, while there is few work considering the atomic-molecular BECs with space-modulated nonlinearities. Here, we obtain two kinds of Jacobi elliptic solutions and a family of rational solutions of the atomic-molecular BECs with trapping potential and space-modulated nonlinearity and consider the effect of three-body interaction on the localized matter wave solutions. The topological properties of the localized nonlinear matter wave for no coupling are analysed: the parity of nonlinear matter wave functions depends only on the principal quantum number n, and the numbers of the density packets for each quantum state depend on both the principal quantum number n and the secondary quantum number l. When the coupling is not zero, the localized nonlinear matter waves given by the rational function, their topological properties are independent of the principal quantum number n, only depend on the secondary quantum number l. The Raman detuning and the chemical potential can change the number and the shape of the density packets. The stability of the Jacobi elliptic solutions depends on the principal quantum number n, while the stability of the rational solutions depends on the chemical potential and Raman detuning. PMID:27403634
Yao, Yu-Qin; Li, Ji; Han, Wei; Wang, Deng-Shan; Liu, Wu-Ming
2016-01-01
The intrinsic nonlinearity is the most remarkable characteristic of the Bose-Einstein condensates (BECs) systems. Many studies have been done on atomic BECs with time- and space- modulated nonlinearities, while there is few work considering the atomic-molecular BECs with space-modulated nonlinearities. Here, we obtain two kinds of Jacobi elliptic solutions and a family of rational solutions of the atomic-molecular BECs with trapping potential and space-modulated nonlinearity and consider the effect of three-body interaction on the localized matter wave solutions. The topological properties of the localized nonlinear matter wave for no coupling are analysed: the parity of nonlinear matter wave functions depends only on the principal quantum number n, and the numbers of the density packets for each quantum state depend on both the principal quantum number n and the secondary quantum number l. When the coupling is not zero, the localized nonlinear matter waves given by the rational function, their topological properties are independent of the principal quantum number n, only depend on the secondary quantum number l. The Raman detuning and the chemical potential can change the number and the shape of the density packets. The stability of the Jacobi elliptic solutions depends on the principal quantum number n, while the stability of the rational solutions depends on the chemical potential and Raman detuning. PMID:27403634
Integrated coherent matter wave circuits
International Nuclear Information System (INIS)
An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry
Conti, C; Conti, Claudio; Trillo, Stefano
2003-01-01
We predict that an ultra-cold Bose gas in an optical lattice can give rise to a new form of condensation, namely matter X waves. These are non-spreading 3D wave-packets which reflect the symmetry of the Laplacian with a negative effective mass along the lattice direction, and are allowed to exist in the absence of any trapping potential even in the limit of non-interacting atoms. This result has also strong implications for optical propagation in periodic structures
Brownian motion of a matter-wave bright soliton moving through a thermal cloud of distinct atoms
McDonald, R. G.; Bradley, A. S.
2016-06-01
Taking an open quantum system approach, we derive a collective equation of motion for the dynamics of a matter-wave bright soliton moving through a thermal cloud of a distinct atomic species. The reservoir interaction involves energy transfer without particle transfer between the soliton and thermal cloud, thus damping the soliton motion without altering its stability against collapse. We derive a Langevin equation for the soliton center-of-mass velocity in the form of an Ornstein-Uhlenbeck process with analytical drift and diffusion coefficients. This collective motion is confirmed by simulations of the full stochastic projected Gross-Pitaevskii equation for the matter-wave field. The system offers a pathway for experimentally observing the elusive energy-damping reservoir interaction and a clear realization of collective Brownian motion for a mesoscopic superfluid droplet.
Kaplan, David E.; Krnjaic, Gordan Z.; Rehermann, Keith R.; Wells, Christopher M.
2009-01-01
We propose that dark matter is dominantly comprised of atomic bound states. We build a simple model and map the parameter space that results in the early universe formation of hydrogen-like dark atoms. We find that atomic dark matter has interesting implications for cosmology as well as direct detection: Protohalo formation can be suppressed below $M_{proto} \\sim 10^3 - 10^6 M_{\\odot}$ for weak scale dark matter due to Ion-Radiation interactions in the dark sector. Moreover, weak-scale dark a...
Agueny, Hicham
2015-07-01
We present results for single and double electron captures in intermediate energies H+ and 2H+ projectiles colliding with a helium target. The processes under investigations are treated using a nonperturbative semiclassical approach in combination with Eikonal approximation to calculate the scattering differential cross sections. The latter reveals pronounced minima and maxima in the scattering angles, in excellent agreement with the recent experimental data. It turns out that the present structure depends strongly on the projectile energy and shows only slight variations with different capture channels. The observed structure demonstrates the analogy of atomic de Broglie's matter-wave scattering with λd B=1.3 -3.2 ×10-3 a.u. and Fraunhofer-type diffraction of light waves.
Negative-Index Media for Matter Waves
Perales, F.; Bocvarski, V.; Baudon, J.; Hamamda, M.; Grucker, J.; Dutier, G.; Mainos, C.; Boustimi, M.; Ducloy, M.
2010-02-01
One reviews the recently introduced field of matter-wave "meta-optics", i.e. the extension of optical negative-index media (NIM) to atom optics. After emphasizing the differences with light meta-optics and particularly the necessary transient character of NIM's in atom optics, we present the way of generating matter-wave NIM's and their general properties: negative refraction, atom meta-lenses. Finally their specific features are reviewed: longitudinal wave packet narrowing associated to a time-reversal effect, transient revivals of evanescent matter waves and atom reflection echoes at a potential barrier.
Matter-Wave Decoherence due to a Gas Environment in an Atom Interferometer
Uys, H; Cronin, A D; Uys, Hermann; Perreault, John D.; Cronin, Alexander D.
2005-01-01
Decoherence due to scattering from background gas particles is observed for the first time in a Mach-Zehnder atom interferometer, and compared with decoherence due to scattering photons. A single theory is shown to describe decoherence due to scattering either atoms or photons. Predictions from this theory are tested by experiments with different species of background gas, and also by experiments with different collimation restrictions on an atom beam interferometer.
Matter-Wave Decoherence due to a Gas Environment in an Atom Interferometer
International Nuclear Information System (INIS)
Decoherence due to scattering from background gas particles is observed for the first time in a Mach-Zehnder atom interferometer, and compared with decoherence due to scattering photons. A single theory is shown to describe decoherence due to scattering either atoms or photons. Predictions from this theory are tested by experiments with different species of background gas, and also by experiments with different collimation restrictions on an atom beam interferometer
Matter-Wave Decoherence due to a Gas Environment in an Atom Interferometer
Uys, Hermann; Perreault, John D.; Cronin, Alexander D.
2005-10-01
Decoherence due to scattering from background gas particles is observed for the first time in a Mach-Zehnder atom interferometer, and compared with decoherence due to scattering photons. A single theory is shown to describe decoherence due to scattering either atoms or photons. Predictions from this theory are tested by experiments with different species of background gas, and also by experiments with different collimation restrictions on an atom beam interferometer.
Matter Waves in Reduced Dimensions: Dipolar-Induced Resonances and Atomic Artificial Crystals
Bartolo, Nicola
2014-01-01
The experimental achievement of Bose-Einstein condensation and Fermi degeneracy with ultracold gases boosted tremendous progresses both in theoretical methods and in the development of new experimental tools. Among them, intriguing possibilities have been opened by the implementation of optical lattices: periodic potentials for neutral atoms created by interfering laser beams. Degenerate gases in optical lattices can be forced in highly anisotropic traps, reducing the effective dimensionality...
Coherent Momentum State Manipulation of Matter Waves
Pötting, Sierk
2004-01-01
This dissertation presents a theoretical analysis of methods to manipulate and control the momentum state of coherent matter waves. Of particular interest is the coherent acceleration of a quantum-degenerate atomic system, which, as a direct consequence of the form of the de Broglie wavelength, results in tunable source of matter waves. Such sources are of considerable importance for a number of potential applications in the field of atom optics, including the development...
Ghezali, S.; Taleb, A.
2008-09-01
A research project at the "Laboratoire d'électronique quantique" consists in a theoretical study of the reflection and diffraction phenomena via an atomic mirror. This poster presents the principle of an atomic mirror. Many groups in the world have constructed this type of atom optics experiments such as in Paris-Orsay-Villetaneuse (France), Stanford-Gaithersburg (USA), Munich-Heidelberg (Germany), etc. A laser beam goes into a prism with an incidence bigger than the critical incidence. It undergoes a total reflection on the plane face of the prism and then exits. The transmitted resulting wave out of the prism is evanescent and repulsive as the frequency detuning of the laser beam compared to the atomic transition δ = ωL-ω0 is positive. The cold atomic sample interacts with this evanescent wave and undergoes one or more elastic bounces by passing into backward points in its trajectory because the atoms' kinetic energy (of the order of the μeV) is less than the maximum of the dipolar potential barrier ℏΩ2/Δ where Ω is the Rabi frequency [1]. In fact, the atoms are cooled and captured in a magneto-optical trap placed at a distance of the order of the cm above the prism surface. The dipolar potential with which interact the slow atoms is obtained for a two level atom in a case of a dipolar electric transition (D2 Rubidium transition at a wavelength of 780nm delivered by a Titane-Saphir laser between a fundamental state Jf = l/2 and an excited state Je = 3/2). This potential is corrected by an attractive Van der Waals term which varies as 1/z3 in the Lennard-Jones approximation (typical atomic distance of the order of λ0/2π where λ0 is the laser wavelength) and in 1/z4 if the distance between the atom and its image in the dielectric is big in front of λ0/2π. This last case is obtained in a quantum electrodynamic calculation by taking into account an orthornormal base [2]. We'll examine the role of spontaneous emission for which the rate is inversely
Cavity QED Detection of Interfering Matter Waves
Bourdel, T; Donner, T.; Ritter, S; Öttl, A.; Köhl, M.; Esslinger, T.
2005-01-01
We observe the build-up of a matter wave interference pattern from single atom detection events in a double-slit experiment. The interference arises from two overlapping atom laser beams extracted from a Rubidium Bose-Einstein condensate. Our detector is a high-finesse optical cavity which realizes the quantum measurement of the presence of an atom and thereby projects delocalized atoms into a state with zero or one atom in the resonator. The experiment reveals simultaneously the granular and...
Dynamics of evanescent matter waves in negative-index media
Hamamda, M.; Bocvarski, V.; Perales, F.; Baudon, J.; Dutier, G.; Mainos, C.; Boustimi, M.; Ducloy, M.
2010-11-01
Semi-evanescent and evanescent matter waves produced by an atom wave packet impinging on a repulsive barrier can be back-refracted and reconstructed by the application of negative-index 'comoving' potential pulses. One shows that those collapses and revivals generate a matter wave confined on both sides of the barrier border ('surface matter wave') and should be observable via the retardation of atom reflection from the barrier interface. This property, joined to the possibility recently demonstrated of inducing negative refraction of atom waves, makes such potentials a matter-wave counterpart of negative-index materials or 'meta materials' well known in light optics.
Creation of matter wave Bessel beams
Ryu, C.; Henderson, K. C.; Boshier, M. G.
2013-01-01
Bessel beams are plane waves with amplitude profiles described by Bessel functions. They are important because of their property of limited diffraction and their capacity to carry orbital angular momentum. Here we report the creation of a Bessel beam of de Broglie matter waves. The Bessel beam is produced by the free evolution of a thin toroidal atomic Bose-Einstein condensate (BEC) which has been set into rotational motion. By attempting to stir it at different rotation rates, we show that t...
Negative-Index Media for Matter-Wave Optics
Baudon, J.; Hamamda, M.; Grucker, J.; Boustimi, M.; Perales, F.; Dutier, G.; Ducloy, M.
2009-04-01
We consider the extension of optical metamaterials to matter waves and then the down scaling of metaoptics to nanometric wavelengths. We show that the generic property of pulsed comoving magnetic fields allows us to fashion the wave-number dependence of the atomic phase shift. It can be used to produce a transient negative group velocity of an atomic wave packet, which results into a negative refraction of the matter wave. Application to slow metastable argon atoms Ar*(P23) shows that the device is able to operate either as an efficient beam splitter or an atomic metalens.
Negative-Index Media for Matter-Wave Optics
International Nuclear Information System (INIS)
We consider the extension of optical metamaterials to matter waves and then the down scaling of metaoptics to nanometric wavelengths. We show that the generic property of pulsed comoving magnetic fields allows us to fashion the wave-number dependence of the atomic phase shift. It can be used to produce a transient negative group velocity of an atomic wave packet, which results into a negative refraction of the matter wave. Application to slow metastable argon atoms Ar*(3P2) shows that the device is able to operate either as an efficient beam splitter or an atomic metalens
Matter wave lensing to picokelvin temperatures
Kovachy, Tim; Sugarbaker, Alex; Dickerson, Susannah M; Donnelly, Christine A; Overstreet, Chris; Kasevich, Mark A
2014-01-01
Using a matter wave lens and a long time-of-flight, we cool an ensemble of Rb-87 atoms in two dimensions to an effective temperature of less than $50^{+50}_{-30}$ pK. A short pulse of red-detuned light generates an optical dipole force that collimates the ensemble. We also report a three-dimensional magnetic lens that substantially reduces the chemical potential of evaporatively cooled ensembles with high atom number. These cooling techniques yield bright, collimated sources for precision atom interferometry. By observing such low temperatures, we set limits on proposed modifications to quantum mechanics.
Inversion of an Atomic Wave Packet in a Circularly Polarized Electromagnetic Wave
Institute of Scientific and Technical Information of China (English)
ZENG Gao-Jian
2001-01-01
We study behavior of an atomic wave packet in a circularly polarized electromagnetic wave, and particularly calculate the atomic inversion of the wave packet. A general method of calculation is presented. The results are interesting. For example, if the wave packet is very narrow or/and the interaction is very strong, no matter the atom is initially in its ground state or excited state, the atomic inversion approaches zero as time approaches infinity. If the atom is initially in its ground state and excited state with the probability 1/2 respectively, and if the momentum density is an even function, then the atomic inversion equals zero at any time.``
Time reversal in matter-wave optics
Hamamda, M.; Perales, F.; Dutier, G.; Mainos, C.; Baudon, J.; Boustimi, M.; Ducloy, M.
2011-01-01
The evolution of atomic wave packets experiencing so-called comoving potential pulses is examined theoretically, in the framework of the stationary-phase approximation. The negative refraction induced by this potential is a characteristic property of negative-index media, the atomic counterpart of negative-index materials of light optics. A novel process, specific of negative-index for matter waves, is evidenced, namely a narrowing of the wave packet transiently counterbalancing the natural spreading. This is the manifestation of a general property of negative-index media, i.e. a time reversal effect. It is shown that, for a statistical ensemble of wave packets leading to a moderate dispersion of the times of flight, this time reversal phenomenon should be observable.
Fermionic condensation in ultracold atoms, nuclear matter and neutron stars
Salasnich, Luca
2013-01-01
We investigate the Bose-Einstein condensation of fermionic pairs in three different superfluid systems: ultracold and dilute atomic gases, bulk neutron matter, and neutron stars. In the case of dilute gases made of fermionic atoms the average distance between atoms is much larger than the effective radius of the inter-atomic potential. Here the condensation of fermionic pairs is analyzed as a function of the s-wave scattering length, which can be tuned in experiments by using the technique of...
Matter waves with angular momentum
Bracher, C; Kleber, M; Bracher, Christian; Kramer, Tobias; Kleber, Manfred
2003-01-01
An alternative description of quantum scattering processes rests on inhomogeneous terms amended to the Schr\\"odinger equation. We detail the structure of sources that give rise to multipole scattering waves of definite angular momentum, and introduce pointlike multipole sources as their limiting case. Partial wave theory is recovered for freely propagating particles. We obtain novel results for ballistic scattering in an external uniform force field, where we provide analytical solutions for both the scattering waves and the integrated particle flux. As an illustration of the theory, we predict some properties of vortex-bearing atom laser beams outcoupled from a rotating Bose--Einstein condensate under the influence of gravity.
Cold Matter Assembled Atom-by-Atom
Endres, Manuel; Keesling, Alexander; Levine, Harry; Anschuetz, Eric R; Krajenbrink, Alexandre; Senko, Crystal; Vuletic, Vladan; Greiner, Markus; Lukin, Mikhail D
2016-01-01
The realization of large-scale fully controllable quantum systems is an exciting frontier in modern physical science. We use atom-by-atom assembly to implement a novel platform for the deterministic preparation of regular arrays of individually controlled cold atoms. In our approach, a measurement and feedback procedure eliminates the entropy associated with probabilistic trap occupation and results in defect-free arrays of over 50 atoms in less than 400 ms. The technique is based on fast, real-time control of 100 optical tweezers, which we use to arrange atoms in desired geometric patterns and to maintain these configurations by replacing lost atoms with surplus atoms from a reservoir. This bottom-up approach enables controlled engineering of scalable many-body systems for quantum information processing, quantum simulations, and precision measurements.
Dynamics of matter wave solitons
Polo Gómez, Juan
2012-01-01
Treball final de màster oficial fet en col·laboració amb Universitat Autònoma de Barcelona (UAB), Universitat de Barcelona (UB) i Institut de Ciències Fotòniques (ICFO) [ANGLÈS] We study the implementation of a matter wave bright soliton interferometer formed by a Gaussian potential barrier placed at the center of a harmonic trap potential. After numerically evaluating the transmission coefficient of the potential barrier as a function of the ratio between the kinetic energy of an incident...
Wave Dark Matter and Dwarf Spheroidal Galaxies
Parry, Alan R
2013-01-01
We explore a model of dark matter called wave dark matter (also known as scalar field dark matter and boson stars) which has recently been motivated by a new geometric perspective by Bray. Wave dark matter describes dark matter as a scalar field which satisfies the Einstein-Klein-Gordon equations. These equations rely on a fundamental constant $\\Upsilon$ (also known as the "mass term" of the Klein-Gordon equation). Specifically, in this dissertation, we study spherically symmetric wave dark matter and compare these results with observations of dwarf spheroidal galaxies as a first attempt to compare the implications of the theory of wave dark matter with actual observations of dark matter. This includes finding a first estimate of the fundamental constant $\\Upsilon$. The majority of this thesis has also been presented by the author in three separate shorter papers with arXiv reference codes [arXiv:1210.5269 [gr-qc
Axion Dark Matter Detection using Atomic Transitions
Sikivie, P
2014-01-01
Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.
Neutron Matter Wave Quantum Optics
Rauch, Helmut
2012-06-01
Neutron matter-wave optics provides the basis for new quantum experiments and a step towards applications of quantum phenomena. Most experiments have been performed with a perfect crystal neutron interferometer where widely separated coherent beams can be manipulated individually. Various geometric phases have been measured and their robustness against fluctuation effects has been proven, which may become a useful property for advanced quantum communication. Quantum contextuality for single particle systems shows that quantum correlations are to some extent more demanding than classical ones. In this case entanglement between external and internal degrees of freedom offers new insights into basic laws of quantum physics. Non-contextuality hidden variable theories can be rejected by arguments based on the Kochen-Specker theorem.
Delva, Pacôme; Angonin, Marie-Christine; Tourrenc, Philippe
2006-01-01
We calculate and compare the response of light wave interferometers and matter wave interferometers to gravitational waves. We find that metric matter wave interferometers will not challenge kilometric light wave interferometers such as Virgo or LIGO, but could be a good candidate for the detection of very low frequency gravitational waves.
Quantum noise limits to matter-wave interferometry
Scully, Marlan O.; Dowling, Jonathan P.
1994-01-01
We derive the quantum limits for an atomic interferometer in which the atoms obey either Bose-Einstein or Fermi-Dirac statistics. It is found that the limiting quantum noise is due to the uncertainty associated with the particle sorting between the two branches of the interferometer. As an example, the quantum-limited sensitivity of a matter-wave gyroscope is calculated and compared with that of laser gyroscopes.
Bigravitons as dark matter and gravitational waves
Aoki, Katsuki
2016-01-01
We consider the possibility that the massive graviton is a viable candidate of dark matter in the context of bimetric gravity. We first derive the energy-momentum tensor of the massive graviton and show that it indeed behaves as that of dark matter fluid. We then discuss a production mechanism and the present abundance of massive gravitons as dark matter. Since the metric to which ordinary matter fields couple is a linear combination of the two mass eigenstates of bigravity, production of massive gravitons, i.e. the dark matter particles, is inevitably accompanied by generation of massless gravitons, i.e. the gravitational waves. Therefore, in this scenario some information about dark matter in our universe is encoded in gravitational waves. For instance, if LIGO detects gravitational waves generated by the preheating after inflation then the massive graviton with the mass of $\\sim 0.01$ GeV is a candidate of the dark matter.
Institute of Scientific and Technical Information of China (English)
伍细如
2015-01-01
proton emits energy wave, electron could sits any position away from nucleus, but be the most stable just when it sits at the trough of energy wave, and this position accords with Bohr radius and Schr?dinger equation.
Excitation of knotted vortex lines in matter waves
Maucher, F.; Gardiner, S. A.; Hughes, I. G.
2016-06-01
We study the creation of knotted ultracold matter waves in Bose–Einstein condensates via coherent two-photon Raman transitions with a Λ level configuration. The Raman transition allows an indirect transfer of atoms from the internal state | a> to the target state | b> via an excited state | e> , that would be otherwise dipole-forbidden. This setup enables us to imprint three-dimensional knotted vortex lines embedded in the probe field to the density in the target state. We elaborate on experimental feasibility as well as on subsequent dynamics of the matter wave.
Nonlinear optics of matter waves
Goldstein, E. V.; Moore, M. G.; Zobay, O.; Meystre, P.
1998-01-01
We give a brief overview of the way atomic physics is now developing in a way reminiscent of the optics revolution of the 1960's. Thanks in particular to recent developments in atomic trapping and cooling, the new field of atom optics is rapidly leading to exciting new developments such as nonlinear atom optics and quantum atom optics. We illustrate these developments with examples out of our own research.
Theoretical study of ghost imaging with cold atomic waves under the condition of partial coherence
International Nuclear Information System (INIS)
A matter wave ghost imaging mechanism is proposed and demonstrated theoretically. This mechanism is based on the Talbot-Lau effect. Periodic gratings of matter wave density, which appear as a result of interference of atoms diffracted by pulses of an optical standing wave, are utilized to produce the reference wave and the signal wave simultaneously for the ghost imaging. An advantage of this mechanism is that during the imaging process, the beam-splitter is not needed, which highly simplifies the experimental setup and makes the ghost imaging possible in the field of matter wave
Dephasing dynamics of Rydberg atom spin waves
Bariani, F; Kennedy, T A B
2012-01-01
A theory of Rydberg atom interactions is used to derive analytical forms for the spin wave pair correlation function in laser-excited cold-atom vapors. This function controls the quantum statistics of light emission from dense, inhomogeneous clouds of cold atoms of various spatial dimensionalities. The results yield distinctive scaling behaviors on the microsecond timescale, including generalized exponential decay. A detailed comparison is presented with a recent experiment on a cigar-shaped atomic ensemble [Y. Dudin and A. Kuzmich, Science 336, 887 (2012)], in which Rb atoms are excited to a set of Rydberg levels.
Quantum interference of molecules -- probing the wave nature of matter
Venugopalan, Anu
2012-01-01
The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to i...
Vector Dark Matter Detection using Quantum Jump of Atoms
Yang, Qiaoli
2016-01-01
Hidden sector $U(1)$ vector bosons created from inflationary fluctuations can be a substantial fraction of dark matter if their mass is around $10^{-5}$eV which is the order of the Lamb-shift between S wave and P wave in atoms. Due to the creation mechanism, the dark matter vector bosons are condensate with a very small velocity dispersion which makes their energy spectral density $\\rho_{cdm}/\\Delta E$ very high therefore boost the dark electric dipole transition rates in cooling atoms or ions if the energy gap between states equals the mass of vector bosons. The energy difference between quantum states in atoms can be tuned using the Zeeman effect. In addition, the excited state of atoms can be pumped into a highly excited state, order of eV above the ground state, with a tunable laser. The laser frequency is set so no other states will be excited. The highly excited state with a short lifetime then spontaneously emits photon which can be detected. Choices of target material are many depending on facility of...
Matter wave propagation through microstructured waveguides*
International Nuclear Information System (INIS)
Full text: Significant experimental progress in recent years has been seen in the field of 'atom chips', ie integrated atom optics, where trapping, propagation and manipulation of ultracold atoms have all been done above a single microchip surface. Our theoretical efforts have been focussed on exploring the nature of wave propagation through such microstructured waveguides. We present here a smorgasbord of fundamental physics, ranging from wave excitations and quantum/classical correspondence, through to interference-based vortex production and dispersion management. Copyright (2005) Australian Institute of Physics
Atomic processes in matter-antimatter interactions
International Nuclear Information System (INIS)
Atomic processes dominate antiproton stopping in matter at nearly all energies of interest. They significantly influence or determine the antiproton annihilation rate at all energies around or below several MeV. This article reviews what is known about these atomic processes. For stopping above about 10 eV the processes are antiproton-electron collisions, effective at medium keV through high MeV energies, and elastic collisions with atoms and adiabatic ionization of atoms, effective from medium eV through low keB energies. For annihilation above about 10 eV is the enhancement of the antiproton annihilation rate due to the antiproton-nucleus coulomb attraction, effective around and below a few tens of MeV. At about 10 eV and below, the atomic rearrangement/annihilation process determines both the stopping and annihilation rates. Although a fair amount of theoretical and some experimental work relevant to these processes exist, there are a number of energy ranges and material types for which experimental data does not exist and for which the theoretical information is not as well grounded or as accurate as desired. Additional experimental and theoretical work is required for accurate prediction of antiproton stopping and annihilation for energies and material relevant to antiproton experimentation and application
Scalar Field (Wave) Dark Matter
Matos, T
2016-01-01
Recent high-quality observations of dwarf and low surface brightness (LSB) galaxies have shown that their dark matter (DM) halos prefer flat central density profiles. On the other hand the standard cold dark matter model simulations predict a more cuspy behavior. Feedback from star formation has been widely used to reconcile simulations with observations, this might be successful in field dwarf galaxies but its success in low mass galaxies remains uncertain. One model that have received much attention is the scalar field dark matter model. Here the dark matter is a self-interacting ultra light scalar field that forms a cosmological Bose-Einstein condensate, a mass of $10^{-22}$eV/c$^2$ is consistent with flat density profiles in the centers of dwarf spheroidal galaxies, reduces the abundance of small halos, might account for the rotation curves even to large radii in spiral galaxies and has an early galaxy formation. The next generation of telescopes will provide better constraints to the model that will help...
Matter-wave recombiners for trapped Bose-Einstein condensates
Berrada, T.; van Frank, S.; Bücker, R.; Schumm, T.; Schaff, J.-F.; Schmiedmayer, J.; Julía-Díaz, B.; Polls, A.
2016-06-01
Interferometry with trapped atomic Bose-Einstein condensates (BECs) requires the development of techniques to recombine the two paths of the interferometer and map the accumulated phase difference to a measurable atom number difference. We have implemented and compared two recombining procedures in a double-well-based BEC interferometer. The first procedure utilizes the bosonic Josephson effect and controlled tunneling of atoms through the potential barrier, similar to laser light in an optical fiber coupler. The second one relies on the interference of the reflected and transmitted parts of the BEC wave function when impinging on the potential barrier, analogous to light impinging on a half-silvered mirror. Both schemes were implemented successfully, yielding an interferometric contrast of ˜20 % and 42% respectively. Building efficient matter-wave recombiners represents an important step towards the coherent manipulation of external quantum superposition states of BECs.
Astrophysical constraints on millicharged atomic dark matter
Kvam, Audrey K
2014-01-01
Some models of inelastic dark matter posit the existence of bound states under some new $U(1)'$ gauge symmetry. If this new dark photon kinetically mixes with the standard model photon, then the constituent particles in these bound states can acquire a fractional electric charge. This electric charge renders a dark-matter medium dispersive. We compute this frequency-dependent index of refraction for such a medium and use the frequency-dependent arrival time of light from astrophysical sources to constrain the properties of dark atoms in the medium. Using optical-wavelength observations from the Crab Pulsar, we find the electric millicharge of dark (electrons) protons to be smaller than the electric charge $e$ for dark atom masses below 100 keV, assuming a dark fine structure constant $\\boldsymbol{\\alpha}=1$. We estimate that future broadband observations of gamma-ray bursts can produce constraints on the millicharge of dark atoms with masses in the keV range that are competitive with existing collider constra...
Production and manipulation of wave packets from ultracold atoms in an optical lattice
DEFF Research Database (Denmark)
Pedersen, Poul Lindholm; Gajdacz, Miroslav; Winter, Nils;
2013-01-01
system. The modulation technique also allows for a controllable transfer (deexcitation) of atoms from such wave packets to a state bound by the lattice. Thus, it acts as a beam splitter for matter waves that can selectively address different bands, enabling the preparation of atoms in localized states....... The combination of wave packet creation and deexcitation closely resembles the well-known method of pump-probe spectroscopy. Here, we use the deexcitation for spectroscopy of the anharmonicity of the combined potential. Finally, we demonstrate that lattice modulation can be used to excite matter wave...
Atom laser based on four-wave mixing with Bose-Einstein condensates in nonlinear lattices
Wasak, T.; Konotop, V. V.; Trippenbach, M.
2013-12-01
Optical lattices are typically used to modify the dispersion relation of the matter wave, in particular, to ensure resonant conditions for multiwave interactions. Here we propose an alternative mechanism of wave interactions. It can be implemented using a nonlinear lattice and modifies the momentum conservation law of the interacting atoms, leaving the energy conservation unchanged. We propose to apply this phenomenon to construct an atom laser via a resonant four-wave mixing process.
Detecting inertial effects with airborne matter-wave interferometry
Geiger, Remi; Stern, Guillaume; Zahzam, Nassim; Cheinet, Patrick; Battelier, Baptiste; Villing, André; Moron, Frédéric; Lours, Michel; Bidel, Yannick; Bresson, Alexandre; Landragin, Arnaud; Bouyer, Philippe
2011-01-01
Inertial sensors relying on atom interferometry offer a breakthrough advance in a variety of applications, such as inertial navigation, gravimetry or ground- and space-based tests of fundamental physics. These instruments require a quiet environment to reach their performance and using them outside the laboratory remains a challenge. Here we report the first operation of an airborne matter-wave accelerometer set up aboard a 0g plane and operating during the standard gravity (1g) and microgravity (0g) phases of the flight. At 1g, the sensor can detect inertial effects more than 300 times weaker than the typical acceleration fluctuations of the aircraft. We describe the improvement of the interferometer sensitivity in 0g, which reaches 2 x 10-4 ms-2 / \\surdHz with our current setup. We finally discuss the extension of our method to airborne and spaceborne tests of the Universality of free fall with matter waves.
An Atomic Gravitational Wave Interferometric Sensor (AGIS)
Energy Technology Data Exchange (ETDEWEB)
Dimopoulos, Savas; /Stanford U., Phys. Dept.; Graham, Peter W.; /SLAC; Hogan, Jason M.; Kasevich, Mark A.; /Stanford U., Phys. Dept.; Rajendran, Surjeet; /SLAC /Stanford U., Phys. Dept.
2008-08-01
We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford 10m atom interferometer presently under construction. Each configuration compares two widely separated atom interferometers run using common lasers. The signal scales with the distance between the interferometers, which can be large since only the light travels over this distance, not the atoms. The terrestrial experiment with baseline {approx} 1 km can operate with strain sensitivity {approx} 10{sup -19}/{radical}Hz in the 1 Hz-10 Hz band, inaccessible to LIGO, and can detect gravitational waves from solar mass binaries out to megaparsec distances. The satellite experiment with baseline {approx} 1000 km can probe the same frequency spectrum as LISA with comparable strain sensitivity {approx} 10{sup -20}/{radical}Hz. The use of ballistic atoms (instead of mirrors) as inertial test masses improves systematics coming from vibrations, acceleration noise, and significantly reduces spacecraft control requirements. We analyze the backgrounds in this configuration and discuss methods for controlling them to the required levels.
Using Atomic Clocks to Detect Gravitational Waves
Loeb, Abraham
2015-01-01
Atomic clocks have recently reached a fractional timing precision of $<10^{-18}$. We point out that an array of atomic clocks, distributed along the Earth's orbit around the Sun, will have the sensitivity needed to detect the time dilation effect of mHz gravitational waves (GWs), such as those emitted by supermassive black hole binaries at cosmological distances. Simultaneous measurement of clock-rates at different phases of a passing GW provides an attractive alternative to the interferometric detection of temporal variations in distance between test masses separated by less than a GW wavelength, currently envisioned for the eLISA mission.
Observation of Atom-Wave Beats Using a Kerr Modulator for Atom Waves.
Décamps, B; Gillot, J; Vigué, J; Gauguet, A; Büchner, M
2016-02-01
A phase modulation puts the atom in a coherent superposition of quantum states with different kinetic energies. We have detected the interference of such modulated waves at the output of our atom interferometer, and we have observed beats at the difference of the modulation frequencies and its harmonics, in good agreement with theory. The phase modulations were produced by a Kerr phase modulator, i.e., by the propagation of the atom wave in a time-dependent electric field. An extension of this technique to electron interferometry should open the way to very high temporal resolution in electron microscopy. PMID:26894710
Self-induced dipole force and filamentation instability of a matter wave
DEFF Research Database (Denmark)
Saffman, M.
1998-01-01
The interaction of copropagating electromagnetic and matter waves is described with a set of coupled higher-order nonlinear Schrodinger equations. Optical self-focusing modulates an initially planar wave leading to the generation of dipole forces on the atoms. Atomic channeling due to the dipole...... forces leads, in the nonlinear regime, to filamentation of the atomic beam. Instability growth rates are calculated for atomic beams with both low and high phase space densities. In one transverse dimension an exact solution is found that describes a coupled optical and atomic soliton....
Wave impedance of an atomically thin crystal.
Merano, Michele
2015-11-30
I propose an expression for the electromagnetic wave impedance of a two-dimensional atomic crystal, and I deduce the Fresnel coefficients in terms of this quantity. It is widely known that a two-dimensional crystal can absorb light, if its conductivity is different from zero. It is less emphasized that they can also store a certain amount of electromagnetic energy. The concept of impedance is useful to quantify this point. PMID:26698783
Matter waves from quantum sources in a force field
Kramer, T; Kleber, M; Kramer, Tobias; Bracher, Christian; Kleber, Manfred
2002-01-01
Localized scattering phenomena may result in the formation of stationary matter waves originating from a compact region in physical space. Mathematically, such waves are advantageously expressed in terms of quantum sources that are introduced into the Schr\\"odinger equation. The source formalism yields direct access to the scattering wave function, particle distribution, and total current. As an example, we study emission from three-dimensional Gaussian sources into a homogeneous force field. This model describes the behaviour of an atom laser supplied by an ideal Bose-Einstein condensate under the influence of gravity. We predict a strong dependence of the beam profile on the condensate size and the presence of interference phenomena recently observed in photodetachment experiments.
Matter-Wave Interferometery at BYU
Erickson, Christopher; Archibald, James; Merrill, Daniel; Bennett, Aaron; Durfee, Dallin
2009-10-01
We report on the progress of two matter-wave interferometers at BYU. The first device is a thermal-beam Ramsey-Bord'e calcium interferometer. The second device is an ion interferometer based on a laser-cooled ^87Sr^+ beam which will be split and recombined using stimulated Raman transitions. Design considerations, instrumentation development, and possible applications of the devices will be discussed.
Shock wave formation in hot nuclear matter
International Nuclear Information System (INIS)
Assuming that nuclear matter can be treated as a perfect fluid, we study the propagation of perturbations in the baryon density at high temperature. The equation of state is derived from the non-linear Walecka model. The expansion of the Euler and continuity equations of relativistic hydrodynamics around equilibrium configurations lead to the breaking wave equation for the density perturbation. We solve it numerically for this perturbation and follow the propagation of the initial pulses. (author)
Coherent transport of matter waves in disordered optical potentials
Energy Technology Data Exchange (ETDEWEB)
Kuhn, Robert
2007-07-01
The development of modern techniques for the cooling and the manipulation of atoms in recent years, and the possibility to create Bose-Einstein condensates and degenerate Fermi gases and to load them into regular optical lattices or disordered optical potentials, has evoked new interest for the disorder-induced localization of ultra-cold atoms. This work studies the transport properties of matter waves in disordered optical potentials, which are also known as speckle potentials. The effect of correlated disorder on localization is first studied numerically in the framework of the Anderson model. The relevant transport parameters in the configuration average over many different realizations of the speckle potential are then determined analytically, using self-consistent diagrammatic perturbation techniques. This allows to make predictions for a possible experimental observation of coherent transport phenomena for cold atoms in speckle potentials. Of particular importance are the spatial correlations of the speckle fluctuations, which are responsible for the anisotropic character of the single scattering processes in the effective medium. Coherent multiple scattering leads to quantum interference effects, which entail a renormalization of the diffusion constant as compared to the classical description. This so-called weak localization of matter waves is studied as the underlying mechanism for the disorder-driven transition to the Anderson-localization regime, explicitly taking into account the correlations of the speckle fluctuations. (orig.)
Coherent transport of matter waves in disordered optical potentials
International Nuclear Information System (INIS)
The development of modern techniques for the cooling and the manipulation of atoms in recent years, and the possibility to create Bose-Einstein condensates and degenerate Fermi gases and to load them into regular optical lattices or disordered optical potentials, has evoked new interest for the disorder-induced localization of ultra-cold atoms. This work studies the transport properties of matter waves in disordered optical potentials, which are also known as speckle potentials. The effect of correlated disorder on localization is first studied numerically in the framework of the Anderson model. The relevant transport parameters in the configuration average over many different realizations of the speckle potential are then determined analytically, using self-consistent diagrammatic perturbation techniques. This allows to make predictions for a possible experimental observation of coherent transport phenomena for cold atoms in speckle potentials. Of particular importance are the spatial correlations of the speckle fluctuations, which are responsible for the anisotropic character of the single scattering processes in the effective medium. Coherent multiple scattering leads to quantum interference effects, which entail a renormalization of the diffusion constant as compared to the classical description. This so-called weak localization of matter waves is studied as the underlying mechanism for the disorder-driven transition to the Anderson-localization regime, explicitly taking into account the correlations of the speckle fluctuations. (orig.)
Chiral density wave in nuclear matter
International Nuclear Information System (INIS)
Inspired by recent work on inhomogeneous chiral condensation in cold, dense quark matter within models featuring quark degrees of freedom, we investigate the chiral density-wave solution in nuclear matter at zero temperature and nonvanishing baryon number density in the framework of the so-called extended linear sigma model (eLSM). The eLSM is an effective model for the strong interaction based on the global chiral symmetry of quantum chromodynamics (QCD). It contains scalar, pseudoscalar, vector, and axial-vector mesons as well as baryons. In the latter sector, the nucleon and its chiral partner are introduced as parity doublets in the mirror assignment. The eLSM simultaneously provides a good description of hadrons in vacuum as well as nuclear matter ground-state properties. We find that an inhomogeneous phase in the form of a chiral density wave is realized, but only for densities larger than 2.4ρ0, where ρ0 is the nuclear matter ground-state density
Suppression of collapse for matter waves with orbital angular momentum
International Nuclear Information System (INIS)
We explore the influence of the orbital angular momentum on the collapse of vortex-free elliptic clouds of Bose–Einstein condensates with a negative scattering length trapped in a radially symmetric harmonic potential. We show that the number of trapped ultracold atoms corresponding to the collapse threshold can be radically increased for such rotating nonlinear matter waves. Below the threshold the elliptic mode is stable and exhibits periodic oscillations around a stationary rotating state. The frequency of these oscillations is independent of the number of particles and is determined solely by the trapping potential
Dynamics of bright matter-wave solitons in inhomogeneous cigar-type Bose-Einstein condensate
Abdullaev, F. Kh.; Gammal, A.; Tomio, L.
2002-01-01
We discuss the possible observation of a new type of standing nonlinear atomic matter wave in the condensate: the nonlinear impurity mode. It is investigated dynamical effects of a bright soliton in Bose-Einstein-condensed (BEC) systems with local space variations of the two-body atomic scattering length. A rich dynamics is observed in the interaction between the soliton and an inhomogeneity. Processes as trapping, reflection and transmission of the bright matter soliton due to the impurity a...
Manipulating Higher Partial-Wave Atom-Atom Interaction by Strong Photoassoiative Coupling
Deb, Bimalendu; Hazra, Jisha
2009-01-01
We show that it is possible to change not only s-wave but also higher partial wave atom-atom interactions in cold collision in the presence of relatively intense laser fields tuned near a photoassociative transition.
Experimental methods of molecular matter-wave optics
International Nuclear Information System (INIS)
We describe the state of the art in preparing, manipulating and detecting coherent molecular matter. We focus on experimental methods for handling the quantum motion of compound systems from diatomic molecules to clusters or biomolecules. Molecular quantum optics offers many challenges and innovative prospects: already the combination of two atoms into one molecule takes several well-established methods from atomic physics, such as for instance laser cooling, to their limits. The enormous internal complexity that arises when hundreds or thousands of atoms are bound in a single organic molecule, cluster or nanocrystal provides a richness that can only be tackled by combining methods from atomic physics, chemistry, cluster physics, nanotechnology and the life sciences. We review various molecular beam sources and their suitability for matter-wave experiments. We discuss numerous molecular detection schemes and give an overview over diffraction and interference experiments that have already been performed with molecules or clusters. Applications of de Broglie studies with composite systems range from fundamental tests of physics up to quantum-enhanced metrology in physical chemistry, biophysics and the surface sciences. Nanoparticle quantum optics is a growing field, which will intrigue researchers still for many years to come. This review can, therefore, only be a snapshot of a very dynamical process. (review article)
Wave mechanics of the hydrogen atom
Ogilvie, J F
2016-01-01
The hydrogen atom is a system amenable to an exact treatment within Schroedinger's formulation of quantum mechanics according to coordinates in four systems -- spherical polar, paraboloidal, ellipsoidal and spheroconical coordinates; the latter solution is reported for the first time. Applications of these solutions include angular momenta, a quantitative calculation of the absorption spectrum and accurate plots of surfaces of amplitude functions. The shape of an amplitude function, and even the quantum numbers in a particular set to specify such an individual function, depend on the coordinates in a particular chosen system, and are therefore artefacts of that particular coordinate representation within wave mechanics. All discussion of atomic or molecular properties based on such shapes or quantum numbers therefore lacks general significance
A universal matter-wave interferometer with optical gratings
International Nuclear Information System (INIS)
Quantum mechanics was initially developed to describe microscopic processes but scientists quickly came to far-reaching predictions, such as the wave-particle dualism of matter [1,2] or the entanglement of particles [3,4], which often contradict our classical intuition. However, not even a single experiment could falsify any theoretical prediction of quantum mechanics. Today it is the most tested theory in physics. The question of the range and limits of its validity arises. To which extend can systems be macroscopic, complex and massive while retaining their quantum features? Is there a spatial and temporal restriction to the separation of wave functions? Which decoherence mechanisms force systems at macroscopic scales to appear classical? During my thesis I focused theoretically as well as experimentally on matter-wave interferometry with atoms, molecules and molecular clusters. During my 3 month exchange stay in the group of Prof. Müller at the University of California at Berkeley we have carried out an experiment to show the largest space-time area interferometer at that time [5]. Here, matter waves of caesium atoms have been coherently split and recombined up to 8.8 mm and for 500 ms. Key to run this experiment was to compensate for earth´s rotation. Without this compensation the Coriolis force would have prevented the split matter-waves from a precise recombination. The main subject of my thesis at the University of Vienna was the experimental realization of the (first) all Optical Time-domain Ionizing Matter-wave (OTIMA) interferometer [6,7]. It consists of three pulsed nanosecond standing light waves which act on the particles with a well-defined timing sequence. Interference in the time-domain is independent of the particles’ velocities and of their de Broglie wavelengths. This has been demonstrated earlier for atoms by addressing laser light to certain atomic levels [8]. In contrast to that, the OTIMA interferometer uses optical ionization gratings [9
Gyroscopic effects in interference of matter waves
International Nuclear Information System (INIS)
A new gyroscopic interference effect stemming from the Galilean translational factor in the matter wave function is pointed out. In contrast to the well-known Sagnac effect that stems from the geometric phase and leads to a shift of interference fringes, this effect causes slanting of the fringes. We illustrate it by calculations for two split cigar-shaped Bose-Einstein condensates under the conditions of a recent experiment, see Y. Shin et al., Phys. Rev. Lett. 92, 050405 (2004). Importantly, the measurement of slanting obviates the need of a third reference cloud
Gyroscopic effects in interference of matter waves
Tolstikhin, Oleg I.; Morishita, Toru; Watanabe, Shinichi
2005-01-01
A new gyroscopic interference effect stemming from the Galilean translational factor in the matter wave function is pointed out. In contrast to the well-known Sagnac effect that stems from the geometric phase and leads to a shift of interference fringes, this effect causes slanting of the fringes. We illustrate it by calculations for two split cigar-shaped Bose-Einstein condensates under the conditions of a recent experiment, see Y.Shin et al., Phys. Rev. Lett. 92, 050405 (2004). Importantly,...
Transverse multipolar light-matter couplings in evanescent waves
Fernandez-Corbaton, Ivan; Bonod, Nicolas; Rockstuhl, Carsten
2016-01-01
We present an approach to study the interaction between matter and evanescent fields. The approach is based on the decomposition of evanescent plane waves into multipoles of well-defined angular momentum transverse to both decay and propagation directions. We use the approach to identify the origin of the recently observed directional coupling of emitters into guided modes, and of the opposite Zeeman state excitation of atoms near a fiber. We explain how to rigorously quantify both effects, and show that the directionality and the difference in excitation rates grow exponentially with the multipolar order of the light-matter interaction. We also use the approach to study and maximize the transverse torque exerted by an evanescent plane wave onto a given spherical absorbing particle. The maximum occurs at the quadrupolar order of the particle, and for a particular polarization of the plane wave. All the obtained physical insights can be traced back to the two main features of the decomposition of evanescent pl...
Fifteen Years of Cold Matter on the Atom Chip: Promise, Realizations, and Prospects
Keil, Mark; Zhou, Shuyu; Groswasser, David; Japha, Yonathan; Folman, Ron
2016-01-01
Here we review the field of atom chips in the context of Bose-Einstein Condensates (BEC) as well as cold matter in general. Twenty years after the first realization of the BEC and fifteen years after the realization of the atom chip, the latter has been found to enable extraordinary feats: from producing BECs at a rate of several per second, through the realization of matter-wave interferometry, and all the way to novel probing of surfaces and new forces. In addition, technological applications are also being intensively pursued. This review will describe these developments and more, including new ideas which have not yet been realized.
Sensitivity of atom interferometry to ultralight scalar field dark matter
Geraci, Andrew A.; Derevianko, Andrei
2016-01-01
We discuss the use of atom interferometry as a tool to search for Dark Matter (DM) composed of ultra-light scalar fields. Previous work on ultra-light DM detection using accelerometers has considered the possibility of equivalence principle violating effects whereby gradients in the dark matter field can directly produce relative accelerations between media of differing composition. In atom interferometers, we find that time-varying phase signals from oscillatory, or dilaton-like, DM can also...
Wave Dark Matter and the Tully-Fisher Relation
Bray, Hubert L.; Goetz, Andrew S.
2014-01-01
We investigate a theory of dark matter called wave dark matter, also known as scalar field dark matter (SFDM) and boson star dark matter or Bose-Einstein condensate (BEC) dark matter, in spherical symmetry and its relation to the Tully-Fisher relation. We show that fixing the oscillation frequency of wave dark matter near the edge of dark galactic halos implies a Tully-Fisher-like relation for those halos. We then describe how this boundary condition, which is roughly equivalent to fixing the...
Dark Atoms and Puzzles of Dark Matter Searches
Khlopov, M Yu
2014-01-01
The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and particle candidates for cosmological dark matter are the lightest particles that bear new conserved quantum numbers. Dark matter candidates can appear in the new families of quarks and leptons and the existence of new stable charged leptons and quarks is possible, if they are hidden in elusive "dark atoms". Such possibility, strongly restricted by the constraints on anomalous isotopes of light elements, is not excluded in scenarios that predict stable double charged particles. The excessive -2 charged particles are bound in these scenarios with primordial helium in O-helium "atoms", maintaining specific nuclear-interacting form of the dark matter, which may provide an interesting solution for the puzzles of the direct dark matter searches.
Transverse azimuthal dephasing of vortex spin wave in a hot atomic gas
Shi, Shuai; Zhang, Wei; Zhou, Zhi-Yuan; Dong, Ming-Xin; Liu, Shi-Long; Shi, Bao-Sen; Guo, Guang-Can
2016-01-01
Optical fields with orbital angular momentum (OAM) interact with medium have many remarkable properties with its unique azimuthal phase, showing many potential applications in high capacity information processing, high precision measurement etc. The dephasing mechanics of optical fields with OAM in an interface between light and matter plays a vital role in many areas of physics. In this work, we study the transverse azimuthal dephasing of OAM spin wave in a hot atomic gas via OAM storage. The transverse azimuthal phase difference between the control and probe beams is mapped onto the spin wave, which essentially results in dephasing of atomic spin wave. The dephasing of OAM spin wave can be controlled by the parameters of OAM topological charge and beam waist. Our results are helpful for studying OAM light interaction with matter, maybe hold a promise in OAM-based quantum information processing.
Quantum mechanics, matter waves, and moving clocks
Mueller, Holger
2013-01-01
This paper is divided into three parts. In the first (section 1), we demonstrate that all of quantum mechanics can be derived from the fundamental property that the propagation of a matter wave packet is described by the same gravitational and kinematic time dilation that applies to a clock. We will do so in several steps, first deriving the Schroedinger equation for a nonrelativistic particle without spin in a weak gravitational potential, and eventually the Dirac equation in curved space-time describing the propagation of a relativistic particle with spin in strong gravity. In the second part (sections 2-4), we present interesting consequences of the above quantum mechanics: that it is possible to use wave packets as a reference for a clock, to test general relativity, and to realize a mass standard based on a proposed redefinition of the international system of units, wherein the Planck constant would be assigned a fixed value. The clock achieved an absolute accuracy of 4 parts per billion (ppb). The exper...
Matter-wave grating distinguishing conservative and dissipative interactions
Cameron, Robert P.; Götte, Jörg B.; Barnett, Stephen M.; Cotter, J. P.
2016-07-01
We propose an optical grating for matter waves that separates molecules depending on whether their interaction with the light is conservative or dissipative. Potential applications include fundamental tests of quantum mechanics, measurement of molecular properties, and the ability to selectively prepare matter waves with different internal temperatures.
Condensed matter applied atomic collision physics, v.4
Datz, Sheldon
1983-01-01
Applied Atomic Collision Physics, Volume 4: Condensed Matter deals with the fundamental knowledge of collision processes in condensed media.The book focuses on the range of applications of atomic collisions in condensed matter, extending from effects on biological systems to the characterization and modification of solids. This volume begins with the description of some aspects of the physics involved in the production of ion beams. The radiation effects in biological and chemical systems, ion scattering and atomic diffraction, x-ray fluorescence analysis, and photoelectron and Auger spectrosc
The Sagnac effect: 20 years of development in matter-wave interferometry
Barrett, Brynle; Dutta, Indranil; Meunier, Matthieu; Canuel, Benjamin; Gauguet, Alexandre; Bouyer, Philippe; Landragin, Arnaud
2014-01-01
Since the first atom interferometry experiments in 1991, measurements of rotation through the Sagnac effect in open-area atom interferometers has been studied. These studies have demonstrated very high sensitivity which can compete with state-of-the-art optical Sagnac interferometers. Since the early 2000s, these developments have been motivated by possible applications in inertial guidance and geophysics. Most matter-wave interferometers that have been investigated since then are based on two-photon Raman transitions for the manipulation of atomic wave packets. Results from the two most studied configurations, a space-domain interferometer with atomic beams and a time-domain interferometer with cold atoms, are presented and compared. Finally, the latest generation of cold atom interferometers and their preliminary results are presented.
Observation of atom wave phase shifts induced by van der Waals atom-surface interactions
Perreault, J D; Perreault, John D.; Cronin, Alexander D.
2005-01-01
The development of nanotechnology and atom optics relies on understanding how atoms behave and interact with their environment. Isolated atoms can exhibit wave-like (coherent) behaviour with a corresponding de Broglie wavelength and phase which can be affected by nearby surfaces. Here an atom interferometer is used to measure the phase shift of Na atom waves induced by the walls of a 50 nm wide cavity. To our knowledge this is the first direct measurement of the de Broglie wave phase shift caused by atom-surface interactions. The magnitude of the phase shift is in agreement with that predicted by quantum electrodynamics for a non-retarded van der Waals interaction. This experiment also demonstrates that atom-waves can retain their coherence even when atom-surface distances are as small as 10 nm.
Concept of an ionizing time-domain matter-wave interferometer
Nimmrichter, Stefan; Haslinger, Philipp; Hornberger, Klaus; Arndt, Markus
2011-01-01
We discuss the concept of an all-optical and ionizing matter-wave interferometer in the time domain. The proposed setup aims at testing the wave nature of highly massive clusters and molecules, and it will enable new precision experiments with a broad class of atoms, using the same laser system. The propagating particles are illuminated by three pulses of a standing ultraviolet laser beam, which detaches an electron via efficient single photon-absorption. Optical gratings may have periods as ...
Observation of atom wave phase shifts induced by van der Waals atom-surface interactions
Perreault, John D.; Cronin, Alexander D.
2005-01-01
The development of nanotechnology and atom optics relies on understanding how atoms behave and interact with their environment. Isolated atoms can exhibit wave-like (coherent) behaviour with a corresponding de Broglie wavelength and phase which can be affected by nearby surfaces. Here an atom interferometer is used to measure the phase shift of Na atom waves induced by the walls of a 50 nm wide cavity. To our knowledge this is the first direct measurement of the de Broglie wave phase shift ca...
The Sagnac effect: 20 years of development in matter-wave interferometry
Barrett, Brynle; Geiger, Remi; Dutta, Indranil; Meunier, Matthieu; Canuel, Benjamin; Gauguet, Alexandre; Bouyer, Philippe; Landragin, Arnaud
2014-01-01
Since the first atom interferometry experiments in 1991, measurements of rotation through the Sagnac effect in open-area atom interferometers has been studied. These studies have demonstrated very high sensitivity which can compete with state-of-the-art optical Sagnac interferometers. Since the early 2000s, these developments have been motivated by possible applications in inertial guidance and geophysics. Most matter-wave interferometers that have been investigated since then are based on tw...
Massive gravitons as dark matter and gravitational waves
Aoki, Katsuki; Mukohyama, Shinji
2016-07-01
We consider the possibility that the massive graviton is a viable candidate for dark matter in the context of bimetric gravity. We first derive the energy-momentum tensor of the massive graviton and show that it indeed behaves as that of dark matter fluid. We then discuss a production mechanism and the present abundance of massive gravitons as dark matter. Since the metric to which ordinary matter fields couple is a linear combination of the two mass eigenstates of bigravity, production of massive gravitons, i.e., the dark matter particles, is inevitably accompanied by generation of massless gravitons, i.e., the gravitational waves. Therefore, in this scenario some information about dark matter in our Universe is encoded in gravitational waves. For instance, if LIGO detects gravitational waves generated by the preheating after inflation, then the massive graviton with the mass of ˜0.01 GeV is a candidate for dark matter.
Atomic physics precise measurements and ultracold matter
Inguscio, Massimo
2013-01-01
Atomic Physics provides an expert guide to two spectacular new landscapes in physics: precision measurements, which have been revolutionized by the advent of the optical frequency comb, and atomic physics, which has been revolutionized by laser cooling. These advances are not incremental but transformative: they have generated a consilience between atomic and many-body physics, precipitated an explosion of scientific and technological applications, opened new areas of research, and attracted a brilliant generation of younger scientists. The research is advancing so rapidly, the barrage of applications is so dazzling, that students can be bewildered. For both students and experienced scientists, this book provides an invaluable description of basic principles, experimental methods, and scientific applications.
Black Hole Atom as a Dark Matter Particle Candidate
Directory of Open Access Journals (Sweden)
V. I. Dokuchaev
2014-01-01
Full Text Available We propose the new dark matter particle candidate—the “black hole atom,” which is an atom with the charged black hole as an atomic nucleus and electrons in the bound internal quantum states. As a simplified model we consider the the central Reissner-Nordström black hole with the electric charge neutralized by the internal electrons in bound quantum states. For the external observers these objects would look like the electrically neutral Schwarzschild black holes. We suppose the prolific production of black hole atoms under specific conditions in the early universe.
Black Hole Atom as a Dark Matter Particle Candidate
International Nuclear Information System (INIS)
We propose the new dark matter particle candidate—the “black hole atom,” which is an atom with the charged black hole as an atomic nucleus and electrons in the bound internal quantum states. As a simplified model we consider the the central Reissner-Nordström black hole with the electric charge neutralized by the internal electrons in bound quantum states. For the external observers these objects would look like the electrically neutral Schwarzschild black holes. We suppose the prolific production of black hole atoms under specific conditions in the early universe
Observation of Atom Wave Phase Shifts Induced by Van Der Waals Atom-Surface Interactions
International Nuclear Information System (INIS)
The development of nanotechnology and atom optics relies on understanding how atoms behave and interact with their environment. Isolated atoms can exhibit wavelike (coherent) behavior with a corresponding de Broglie wavelength and phase which can be affected by nearby surfaces. Here an atom interferometer is used to measure the phase shift of Na atom waves induced by the walls of a 50 nm wide cavity. To our knowledge this is the first direct measurement of the de Broglie wave phase shift caused by atom-surface interactions. The magnitude of the phase shift is in agreement with that predicted by Lifshitz theory for a nonretarded van der Waals interaction. This experiment also demonstrates that atom waves can retain their coherence even when atom-surface distances are as small as 10 nm
Superposition of Stationary Wave Fields Via Atom Microscopy
Hizbullah; Ali, khan Anwar; Khan, Naveed; Ahmad, Iftikhar; Amin Bacha, Bakht
2015-03-01
We investigate one-dimensional position microscopy of a three-level atom moving through a stationary wave region under the condition of electromagnetically induced transparency. The precise position information of an atom is observed on the resonance absorption and dispersion distribution spectrum of a weak probe field. Single and multiple localization peaks are observed in specific directions of the corresponding wave numbers and phase of the standing wave fields. The strength of space-independent Rabi frequency reduces the position uncertainty in the localized peaks without disturbing the probability of the atom. In a hot atomic medium the localized probability of an atom is reduced which depends upon the temperature of that medium. Our results provide useful applications in the development of laser cooling, atom nanolithography and Bose-Einstein condensation.
Vector Dark Matter Detection using the Quantum Jump of Atoms
Yang, Qiaoli; Di, Haoran
2016-01-01
The hidden sector $U(1)$ vector bosons created from inflationary fluctuations can be a substantial fraction of dark matter if their mass is around $10^{-5}$eV. Due to the creation mechanism, the dark matter vector bosons are a condensate with a very small velocity dispersion, which makes their energy spectral density $\\rho_{cdm}/\\Delta E$ very high. Therefore, the dark electric dipole transition rate in atoms or ions is boosted if the energy gap between atomic states equals the mass of the ve...
Cox, Kevin C; Wu, Baochen; Thompson, James K
2016-01-01
We demonstrate a method to generate spatially homogeneous entangled, spin-squeezed states of atoms appropriate for maintaining a large amount of squeezing even after release into the arm of a matter-wave interferometer or other free space quantum sensor. Using an effective intracavity dipole trap, we allow atoms to move along the cavity axis and time average their coupling to the standing wave used to generate entanglement via collective measurements, demonstrating 11(1) dB of directly observed spin squeezing. Our results show that time averaging in collective measurements can greatly reduce the impact of spatially inhomogeneous coupling to the measurement apparatus.
Concept of an ionizing time-domain matter-wave interferometer
Nimmrichter, Stefan; Hornberger, Klaus; Arndt, Markus
2011-01-01
We discuss the concept of an all-optical and ionizing matter-wave interferometer in the time domain. The proposed setup aims at testing the wave nature of highly massive clusters and molecules, and it will enable new precision experiments with a broad class of atoms, using the same laser system. The propagating particles are illuminated by three pulses of a standing ultraviolet laser beam, which detaches an electron via efficient single photon-absorption. Optical gratings may have periods as small as 80 nm, leading to wide diffraction angles for cold atoms and to compact setups even for very massive clusters. Accounting for the coherent and the incoherent parts of the particle-light interaction, we show that the combined effect of phase and amplitude modulation of the matter waves gives rise to a Talbot-Lau-like interference effect with a characteristic dependence on the pulse delay time.
Modeling Wave Dark Matter in Dwarf Spheroidal Galaxies
Bray, Hubert L
2013-01-01
This paper studies a model of dark matter called wave dark matter (also known as scalar field dark matter and boson stars) which has recently also been motivated by a new geometric perspective by Bray [arXiv:1212.5745]. Wave dark matter describes dark matter as a scalar field which satisfies the Einstein-Klein-Gordon equations. These equations rely on a fundamental constant Upsilon (also known as the "mass term" of the Klein-Gordon equation). In this work, we compare the wave dark matter model to observations to obtain a working value of Upsilon. Specifically, we compare the mass profiles of spherically symmetric static states of wave dark matter to the Burkert mass profiles that have been shown by Salucci et al. [arXiv:1111.1165] to predict well the velocity dispersion profiles of the eight classical dwarf spheroidal galaxies. We show that a reasonable working value for the fundamental constant in the wave dark matter model is Upsilon = 50 yr^{-1}. We also show that under precise assumptions the value of Ups...
Dual Matter-Wave Inertial Sensors in Weightlessness
Barrett, Brynle; Chichet, Laure; Battelier, Baptiste; Lévèque, Thomas; Landragin, Arnaud; Bouyer, Philippe
2016-01-01
Quantum technology based on cold-atom interferometers is showing great promise for fields such as inertial sensing and fundamental physics. However, the best precision achievable on Earth is limited by the free-fall time of the atoms, and their full potential can only be realized in Space where interrogation times of many seconds will lead to unprecedented sensitivity. Various mission scenarios are presently being pursued which plan to implement matter-wave inertial sensors. Toward this goal, we realize the first onboard operation of simultaneous $^{87}$Rb $-$ $^{39}$K interferometers in the weightless environment produced during parabolic flight. The large vibration levels ($10^{-2}~g/\\sqrt{\\rm Hz}$), acceleration range ($0-1.8~g$) and rotation rates ($5$ deg/s) during flight present significant challenges. We demonstrate the capability of our dual-quantum sensor by measuring the E\\"{o}tv\\"{o}s parameter with systematic-limited uncertainties of $1.1 \\times 10^{-3}$ and $3.0 \\times 10^{-4}$ during standard- a...
Laser Source for Atomic Gravity Wave Detector Project
National Aeronautics and Space Administration — Develop an Atom Interferometry-based gravity wave detector (vs Optical Interferometry). Characterize a high power laser. Use Goddard Space Flight Center Mission...
Detecting dark matter waves with precision measurement tools
Derevianko, Andrei
2016-01-01
Virialized Ultra-Light Fields (VULFs) while being viable cold dark matter candidates can also solve the standard model hierarchy problem. Direct searches for VULFs due to their non-particle nature require low-energy precision measurement tools. Here we consider scalar VULF candidates. While the previous proposals have focused on detecting coherent oscillations of the measured signals at the VULF Compton frequencies at the device location, here we point out that VULFs also have a distinct spatial signature, forming dark matter waves. Thereby the discovery reach can be improved by using distributed networks of precision measurement tools. We find the expected dark-matter wave signal by deriving spatio-temporal two-point VULF correlation function. Based on the developed formalism for coherence properties of dark-matter fields, we propose several experiments for dark matter wave detection. In the most basic version, the modifications to already running experiments are minor and only require GPS-assisted time-stam...
Matter-wave dark solitons in optical lattices
International Nuclear Information System (INIS)
We analyse the Floquet-Bloch spectrum of matter waves in Bose-Einstein condensates loaded into single-periodic optical lattices and double-periodic superlattices. In the framework of the Gross-Pitaevskii equation, we describe the structure and analyse the mobility properties of matter-wave dark solitons residing on backgrounds of extended nonlinear Bloch-type states. We demonstrate that interactions between dark solitons can be effectively controlled in optical superlattices
Chiao, R Y; Chiao, Raymond Y.; Speliotopoulos, Achilles D.
2003-01-01
A dynamical, non-Euclidean spacetime geometry in general relativity theory implies the possibility of gravitational radiation. Here we explore novel methods of detecting such radiation from astrophysical sources by means of matter-wave interferometers (MIGOs), using atomic beams emanating from supersonic atomic sources that are further cooled and collimated by means of optical molasses. While the sensitivities of such MIGOs compare favorably with LIGO and LISA, the sizes of MIGOs can be orders of magnitude smaller, and their bandwidths wider. Using a pedagogical approach, we place this problem into the broader context of problems at the intersection of quantum mechanics with general relativity.
Sensitivity of atom interferometry to ultralight scalar field dark matter
Geraci, Andrew A
2016-01-01
We discuss the use of atom interferometry as a tool to search for Dark Matter (DM) composed of ultra-light scalar fields. Previous work on ultra-light DM detection using accelerometers has considered the possibility of equivalence principle violating effects whereby gradients in the dark matter field can directly produce relative accelerations between media of differing composition. In atom interferometers, we find that time-varying phase signals from oscillatory, or dilaton-like, DM can also arise due to changes in the atom rest mass that can occur between light-pulses throughout the interferometer sequence as well as changes in the earth's gravitational field. We estimate that several orders of magnitude of unexplored phase space for light DM fields can be probed with our proposed method.
Atom interferometric gravitational wave detection using heterodyne laser links
Hogan, Jason M
2015-01-01
We propose a scheme based on a heterodyne laser link that allows for long baseline gravitational wave detection using atom interferometry. While the baseline length in previous atom-based proposals is constrained by the need for a reference laser to remain collimated as it propagates between two satellites, here we circumvent this requirement by employing a strong local oscillator laser near each atom ensemble that is phase locked to the reference laser beam. Longer baselines offer a number of potential advantages, including enhanced sensitivity, simplified atom optics, and reduced atomic source flux requirements.
Atomic coherence in nondegenerate four-wave mixing
Institute of Scientific and Technical Information of China (English)
Zuo Zhan-Chun; Sun Jiang; Liu Xia; Mi Xin; Yu Zu-He; Jiang Qian; Fu Pan-Ming; Wu Ling-An
2007-01-01
Two-photon resonant nondegenerate four-wave mixing (NFWM) with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of the NFWM signal, giving rise to a dip with a linewidth that is linearly proportional to the intensity of the coupling field.
Jeans Analysis for Dwarf Spheroidal Galaxies in Wave Dark Matter
Chen, Shu-Rong; Schive, Hsi-Yu; Chiueh, Tzihong
2016-01-01
Observations suggest that dwarf spheroidal (dSph) galaxies exhibit large constant-density cores in the centers, which can hardly be explained by dissipationless cold dark matter simulations. Wave dark matter (${\\psi {\\rm DM}}$), characterized by a single parameter, the dark matter particle mass $m_{\\psi}$, predicts a central soliton core in every galaxy arising from quantum pressure against gravity. Here we apply Jeans analysis to the kinematic data of eight classical dSphs so as to constrain...
Newtonian noise limit in atom interferometers for gravitational wave detection
Vetrano, Flavio; Viceré, Andrea
2013-01-01
In this work we study the influence of the newtonian noise on atom interferometers applied to the detection of gravitational waves, and we compute the resulting limits to the sensitivity in two different configurations: a single atom interferometer, or a pair of atom interferometers operated in a differential configuration. We find that for the instrumental configurations considered, and operating in the frequency range [0.1-10] Hz, the limits would be comparable to those affecting large scal...
Hybridizing matter-wave and classical accelerometers
Energy Technology Data Exchange (ETDEWEB)
Lautier, J.; Volodimer, L.; Hardin, T.; Merlet, S.; Lours, M.; Pereira Dos Santos, F.; Landragin, A., E-mail: arnaud.landragin@obspm.fr [LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 avenue de l' Observatoire, 75014 Paris (France)
2014-10-06
We demonstrate a hybrid accelerometer that benefits from the advantages of both conventional and atomic sensors in terms of bandwidth (DC to 430 Hz) and long term stability. First, the use of a real time correction of the atom interferometer phase by the signal from the classical accelerometer enables to run it at best performance without any isolation platform. Second, a servo-lock of the DC component of the conventional sensor output signal by the atomic one realizes a hybrid sensor. This method paves the way for applications in geophysics and in inertial navigation as it overcomes the main limitation of atomic accelerometers, namely, the dead times between consecutive measurements.
Hybridizing matter-wave and classical accelerometers
Lautier, Jean; Hardin, Thomas; Merlet, Sebastien; Santos, Franck Pereira Dos; Landragin, Arnaud
2014-01-01
We demonstrate a hybrid accelerometer that benefits from the advantages of both conventional and atomic sensors in terms of bandwidth (DC to 430 Hz) and long term stability. First, the use of a real time correction of the atom interferometer phase by the signal from the classical accelerometer enables to run it at best performances without any isolation platform. Second, a servo-lock of the DC component of the conventional sensor output signal by the atomic one realizes a hybrid sensor. This method paves the way for applications in geophysics and in inertial navigation as it overcomes the main limitation of atomic accelerometers, namely the dead times between consecutive measurements.
Shock wave compression of condensed matter a primer
Forbes, Jerry W
2012-01-01
This book introduces the core concepts of the shock wave physics of condensed matter, taking a continuum mechanics approach to examine liquids and isotropic solids. The text primarily focuses on one-dimensional uniaxial compression in order to show the key features of condensed matter’s response to shock wave loading. The first four chapters are specifically designed to quickly familiarize physical scientists and engineers with how shock waves interact with other shock waves or material boundaries, as well as to allow readers to better understand shock wave literature, use basic data analysis techniques, and design simple 1-D shock wave experiments. This is achieved by first presenting the steady one-dimensional strain conservation laws using shock wave impedance matching, which insures conservation of mass, momentum and energy. Here, the initial emphasis is on the meaning of shock wave and mass velocities in a laboratory coordinate system. An overview of basic experimental techniques for measuring pressure...
Dark energy from quantum wave function collapse of dark matter
International Nuclear Information System (INIS)
Dynamical wave function collapse models entail the continuous liberation of a specified rate of energy arising from the interaction of a fluctuating scalar field with the matter wave function. We consider the wave function collapse process for the constituents of dark matter in our universe. Beginning from a particular early era of the universe chosen from physical considerations, the rate of the associated energy liberation is integrated to yield the requisite magnitude of dark energy around the era of galaxy formation. Further, the equation of state for the liberated energy approaches w→-1 asymptotically, providing a mechanism to generate the present acceleration of the universe.
Path integrals, matter waves, and the double slit
Jones, Eric R.; Bach, Roger A.; Batelaan, Herman
2015-11-01
Basic explanations of the double slit diffraction phenomenon include a description of waves that emanate from two slits and interfere. The locations of the interference minima and maxima are determined by the phase difference of the waves. An optical wave, which has a wavelength λ and propagates a distance L, accumulates a phase of 2π L/λ . A matter wave, also having wavelength λ that propagates the same distance L, accumulates a phase of π L/λ , which is a factor of two different from the optical case. Nevertheless, in most situations, the phase difference, {{Δ }}\\varphi , for interfering matter waves that propagate distances that differ by {{Δ }}L, is approximately 2π {{Δ }}L/λ , which is the same value computed in the optical case. The difference between the matter and optical case hinders conceptual explanations of diffraction from two slits based on the matter-optics analogy. In the following article we provide a path integral description for matter waves with a focus on conceptual explanation. A thought experiment is provided to illustrate the validity range of the approximation {{Δ }}\\varphi ≈ 2π {{Δ }}L/λ .
International Nuclear Information System (INIS)
This manuscript provides a theoretical description, sometimes illustrated by experimental results, of several examples of field-matter interaction in various domains of physics, showing how the same basic concepts and theoretical methods may be used in very different physics situations. The issues addressed here are nonlinear field-matter interaction in plasma physics within the framework of classical mechanics (with a particular emphasis on wave-particle interaction), the linear analysis of beam-plasma instabilities in the relativistic regime, and the quantum description of laser-atom interaction, including quantum electrodynamics. Novel methods are systematically introduced in order to solve some very old problems, like the nonlinear counterpart of the Landau damping rate in plasma physics, for example. Moreover, our results directly apply to inertial confinement fusion, laser propagation in an atomic vapor, ion acceleration in a magnetized plasma and the physics of the Reversed Field Pinch for magnetic fusion. (author)
Multiple scattering induced negative refraction of matter waves
Pinsker, Florian
2016-02-01
Starting from fundamental multiple scattering theory it is shown that negative refraction indices are feasible for matter waves passing a well-defined ensemble of scatterers. A simple approach to this topic is presented and explicit examples for systems of scatterers in 1D and 3D are stated that imply negative refraction for a generic incoming quantum wave packet. Essential features of the effective scattering field, densities and frequency spectrum of scatterers are considered. Additionally it is shown that negative refraction indices allow perfect transmission of the wave passing the ensemble of scatterers. Finally the concept of the superlens is discussed, since it is based on negative refraction and can be extended to matter waves utilizing the observations presented in this paper which thus paves the way to ‘untouchable’ quantum systems in analogy to cloaking devices for electromagnetic waves.
Searching for dark matter with optical atomic clocks
Wcislo, Piotr; Bober, Marcin; Cygan, Agata; Lisak, Daniel; Ciurylo, Roman; Zawada, Michal
2016-01-01
One of the most fundamental questions of modern physics is the existence of yet unknown forms of matter and interactions. The total mass density of the Universe appears to be dominated by some hypothetical dark matter (DM). However, beyond its gravitational interaction at galactic scale, little is known about the DM nature and properties. One possibility is that it has a form of stable topological defects built from light scalar fields which, for nonzero DM-SM coupling, would result in transient variations of fundamental constants. Optical atomic clocks, highly sensitive to variations of the fine-structure constant, seem to be natural candidates for such searches. Here we demonstrate the first experimental constraint on the strength of transient DM-SM coupling determined with optical atomic clocks. Instead of measuring the phase difference between two distant clocks we determine a common component of their readouts. We show that our constraint, even for one-day measurement, greatly exceeds previous laboratory...
Parametric amplification of matter waves in dipolar spinor Bose-Einstein condensates
DEFF Research Database (Denmark)
Deuretzbacher, F.; Gebreyesus, G.; Topic, O.;
2010-01-01
Spin-changing collisions may lead under proper conditions to the parametric amplification of matter waves in spinor Bose-Einstein condensates. Magnetic dipole-dipole interactions, although typically very weak in alkali-metal atoms, are shown to play a very relevant role in the amplification process......-field gradients, hence, must be carefully controlled in future experiments, in order to observe clearly the effects of the dipolar interactions in the amplification dynamics....
Localization of Matter Waves in Two-Dimensional Disordered Optical Potentials
International Nuclear Information System (INIS)
We consider ultracold atoms in 2D disordered optical potentials and calculate microscopic quantities characterizing matter wave quantum transport in the noninteracting regime. We derive the diffusion constant as a function of all relevant microscopic parameters and show that coherent multiple scattering induces significant weak localization effects. In particular, we find that even the strong localization regime is accessible with current experimental techniques and calculate the corresponding localization length
Ionization of Atoms by Slow Heavy Particles, Including Dark Matter
Roberts, B. M.; Flambaum, V. V.; Gribakin, G. F.
2016-01-01
Atoms and molecules can become ionized during the scattering of a slow, heavy particle off a bound electron. Such an interaction involving leptophilic weakly interacting massive particles (WIMPs) is a promising possible explanation for the anomalous 9 σ annual modulation in the DAMA dark matter direct detection experiment [R. Bernabei et al., Eur. Phys. J. C 73, 2648 (2013)]. We demonstrate the applicability of the Born approximation for such an interaction by showing its equivalence to the semiclassical adiabatic treatment of atomic ionization by slow-moving WIMPs. Conventional wisdom has it that the ionization probability for such a process should be exponentially small. We show, however, that due to nonanalytic, cusplike behavior of Coulomb functions close to the nucleus this suppression is removed, leading to an effective atomic structure enhancement. We also show that electron relativistic effects actually give the dominant contribution to such a process, enhancing the differential cross section by up to 1000 times.
Ionization of Atoms by Slow Heavy Particles, Including Dark Matter.
Roberts, B M; Flambaum, V V; Gribakin, G F
2016-01-15
Atoms and molecules can become ionized during the scattering of a slow, heavy particle off a bound electron. Such an interaction involving leptophilic weakly interacting massive particles (WIMPs) is a promising possible explanation for the anomalous 9σ annual modulation in the DAMA dark matter direct detection experiment [R. Bernabei et al., Eur. Phys. J. C 73, 2648 (2013)]. We demonstrate the applicability of the Born approximation for such an interaction by showing its equivalence to the semiclassical adiabatic treatment of atomic ionization by slow-moving WIMPs. Conventional wisdom has it that the ionization probability for such a process should be exponentially small. We show, however, that due to nonanalytic, cusplike behavior of Coulomb functions close to the nucleus this suppression is removed, leading to an effective atomic structure enhancement. We also show that electron relativistic effects actually give the dominant contribution to such a process, enhancing the differential cross section by up to 1000 times. PMID:26824537
Focus on modern frontiers of matter wave optics and interferometry
International Nuclear Information System (INIS)
The level of experimental control and the detailed theoretical understanding of matter wave physics have led to a renaissance of experiments testing the very foundations of quantum mechanics and general relativity, as well as to applications in metrology. A variety of interferometric quantum sensors surpasses, or will surpass, the limits of their classical counterparts, for instance in the measurement of frequency and time or forces such as accelerations due to rotation and gravity with applications in basic science, navigation and the search for natural resources. The collection of original articles published in this focus issue of New Journal of Physics is intended as a snapshot of the current research pursued by a number of leading teams working on the development of new matter wave physics, devices and techniques. A number of contributions also stress the close relation between the historic roots of quantum mechanics and aspects of modern quantum information science which are relevant for matter wave physics. (editorial)
Photofragmentation beam splitters for matter-wave interferometry
Dörre, Nadine; Geyer, Philipp; von Issendorff, Bernd; Haslinger, Philipp; Arndt, Markus
2014-01-01
Extending the range of quantum interferometry to a wider class of composite nanoparticles requires new tools to diffract matter-waves. Recently, pulsed photoionization light gratings have demonstrated their suitability for high mass matter-wave physics. Here we extend quantum interference experiments to a new class of particles by introducing photofragmentation beam splitters into time-domain matter-wave interferometry. Photofragmentation gratings can act on objects as different as van der Waals clusters and biomolecules which are thermally unstable and often resilient to single-photon ionization. We present data that demonstrate this coherent beam splitting mechanism with clusters of hexafluorobenzene and we show single-photon depletion gratings based both on fragmentation and ionization for clusters of vanillin.
Strong CMB Constraint On P-Wave Annihilating Dark Matter
An, Haipeng; Zhang, Yue
2016-01-01
We consider a dark sector consisting of dark matter that is a Dirac fermion and a scalar mediator. This model has been extensively studied in the past. If the scalar couples to the dark matter in a parity conserving manner then dark matter annihilation to two mediators is dominated by the P-wave channel and hence is suppressed at very low momentum. The indirect detection constraint from the anisotropy of the Cosmic Microwave Background is usually thought to be absent in the model because of this suppression. In this letter we show that dark matter annihilation to bound states occurs through the S-wave and hence there is a constraint on the parameter space of the model from the Cosmic Microwave Background.
Matter wave interferometry in the light of Schroedinger's wave mechanics
International Nuclear Information System (INIS)
This is a pre-conference abstracts collection for 67 oral presentations and posters, 62 of them are in INIS scope and are treated individually. The subject matters are interferometers (mainly neutron), interferometry experiments and the related interpretation - and epistemological problems of quantum theory. (qui)
Gravitational wave detection with optical lattice atomic clocks
Kolkowitz, Shimon; Pikovski, Igor; Langellier, Nicholas; Lukin, Mikhail D.; Walsworth, Ronald L.; Ye, Jun
2016-01-01
We propose a space-based gravitational wave detector consisting of two spatially separated, drag-free satellites sharing ultra-stable optical laser light over a single baseline. Each satellite contains an optical lattice atomic clock, which serves as a sensitive, narrowband detector of the local frequency of the shared laser light. A synchronized two-clock comparison between the satellites will be sensitive to the effective Doppler shifts induced by incident gravitational waves (GWs) at a lev...
Wave function recombination instability in cold atom interferometers
Stickney, James A.; Zozulya, Alex A.
2002-01-01
Cold atom interferometers use guiding potentials that split the wave function of the Bose-Einstein condensate and then recombine it. We present theoretical analysis of the wave function recombination instability that is due to the weak nonlinearity of the condensate. It is most pronounced when the accumulated phase difference between the arms of the interferometer is close to an odd multiple of PI and consists in exponential amplification of the weak ground state mode by the strong first exci...
Explicitly correlated wave function for a boron atom
Puchalski, Mariusz; Pachucki, Krzysztof
2015-01-01
We present results of high-precision calculations for a boron atom's properties using wave functions expanded in the explicitly correlated Gaussian basis. We demonstrate that the well-optimized 8192 basis functions enable a determination of energy levels, ionization potential, and fine and hyperfine splittings in atomic transitions with nearly parts per million precision. The results open a window to a spectroscopic determination of nuclear properties of boron including the charge radius of the proton halo in the $^8$B nucleus.
Evolutions of matter-wave bright soliton with spatially modulated nonlinearity
Institute of Scientific and Technical Information of China (English)
Yongshan Cheng; Fei Liu
2009-01-01
The evolution characteristics of a matter-wave bright soliton are investigated by means of the variational approach in the presence of spatially varying nonlinearity.It is found that the atom density envelope of the soliton is changed as a result of the spatial variation of the s-wave scattering length.The stable soliton can exist in appropriate initial conditions.The movement of the soliton depends on the sign and value of the coefficient of spatially modulated nonlinearity.These theoretical predictions are confirmed by the full numerical simulations of the one-dimensional Gross-Pitaevskii equation.
Directory of Open Access Journals (Sweden)
Canuel B.
2014-01-01
Full Text Available We are building a hybrid detector of new concept that couples laser and matter-wave interferometry to study sub Hertz variations of the strain tensor of space-time and gravitation. Using a set of atomic interferometers simultaneously manipulated by the resonant optical field of a 200 m cavity, the MIGA instrument will allow the monitoring of the evolution of the gravitational field at unprecedented sensitivity, which will be exploited both for geophysical studies and for Gravitational Waves (GWs detection. This new infrastructure will be embedded into the LSBB underground laboratory, ideally located away from major anthropogenic disturbances and benefitting from very low background noise.
Novel laser controlled variable matter wave beamsplitter.
Theuer, H; Unanyan, R; Habscheid, C; Klein, K; Bergmann, K
1999-01-18
We demonstrate a novel variable beam splitter using a tripod-linkage of atomic states, the physics of which is based on the laser control of the non-adiabatic coupling between two degenerate dark states. This coupling and the splitting ratio is determined by the time delay of the interaction induced by two of the laser beams. PMID:19396260
Matter-wave bright solitons in effective bichromatic lattice potentials
Indian Academy of Sciences (India)
Golam Ali Sekh
2013-08-01
Matter-wave bright solitons in bichromatic lattice potentials are considered and their dynamics for different lattice environments are studied. Bichromatic potentials are created from superpositions of (i) two linear optical lattices and (ii) a linear and a nonlinear optical lattice. Effective potentials are found for the solitons in both bichromatic lattices and a comparative study is done on the dynamics of solitons with respect to the effective potentials. The effects of dispersion on solitons in bichromatic lattices are studied and it is found that the dispersive spreading can be minimized by appropriate combinations of lattice and interaction parameters. Stability of nondispersive matter-wave solitons is checked from phase portrait analysis.
Evidence for a blast wave from compressed nuclear matter
International Nuclear Information System (INIS)
Central collisions of heavy nuclei at c.m. kinetic energies of a few hundred MeV per nucleon produce fireballs of hot, dense nuclear matter. Each fireball explodes, producing a blast wave of nucleons and pions. Several features of the observed cross sections for pions and protons from Ne on Na F at 0.8 GeV/nucleon (lab) are explained by the blast wave, but contradict earlier, purely thermal models. The available energy is equally divided between translational energy of the blast, and thermal motion of the particles in the exploding matter
Multiple scattering induced negative refraction of matter waves
Florian Pinsker
2016-01-01
Starting from fundamental multiple scattering theory it is shown that negative refraction indices are feasible for matter waves passing a well-defined ensemble of scatterers. A simple approach to this topic is presented and explicit examples for systems of scatterers in 1D and 3D are stated that imply negative refraction for a generic incoming quantum wave packet. Essential features of the effective scattering field, densities and frequency spectrum of scatterers are considered. Additionally ...
International Nuclear Information System (INIS)
The wave function of a moderately cold atom in a stationary near-resonant standing light wave delocalizes very fast due to wave packet splitting. However, frequency modulation of the field may suppress packet splitting for some atoms having specific velocities in a narrow range. These atoms remain localized in a small space for a long time. We show that modulated field can not only trap, but also cool the atoms. We perform a numerical experiment with a large atomic ensebmble having wide initial velocity and energy distribution. During the experiment, most of atoms leave the wave while trapped atoms have narrow energy distribution
Strong CMB Constraint On P-Wave Annihilating Dark Matter
An, Haipeng; Wise, Mark B.; Zhang, Yue(Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, CA, 91125, U.S.A.)
2016-01-01
We consider a dark sector consisting of dark matter that is a Dirac fermion and a scalar mediator. This model has been extensively studied in the past. If the scalar couples to the dark matter in a parity conserving manner then dark matter annihilation to two mediators is dominated by the P-wave channel and hence is suppressed at very low momentum. The indirect detection constraint from the anisotropy of the Cosmic Microwave Background is usually thought to be absent in the model because of t...
Conical intersections for light and matter waves
Leykam, Daniel
2016-01-01
We review the design, theory, and applications of two dimensional periodic lattices hosting conical intersections in their energy-momentum spectrum. The best known example is the Dirac cone, where propagation is governed by an effective Dirac equation, with electron spin replaced by a "fermionic" half-integer pseudospin. However, in many systems such as metamaterials, modal symmetries result in the formation of higher order conical intersections with integer or "bosonic" pseudospin. The ability to engineer lattices with these qualitatively different singular dispersion relations opens up many applications, including superior slab lasers, generation of orbital angular momentum, zero-index metamaterials, and quantum simulation of exotic phases of relativistic matter.
Observable induced gravitational waves from an early matter phase
International Nuclear Information System (INIS)
Assuming that inflation is succeeded by a phase of matter domination, which corresponds to a low temperature of reheating Tr 9GeV, we evaluate the spectra of gravitational waves induced in the post-inflationary universe. We work with models of hilltop-inflation with an enhanced primordial scalar spectrum on small scales, which can potentially lead to the formation of primordial black holes. We find that a lower reheat temperature leads to the production of gravitational waves with energy densities within the ranges of both space and earth based gravitational wave detectors
Ground state wave function and energy of the lithium atom
Puchalski, Mariusz; Pachucki, Krzysztof
2006-01-01
Highly accurate nonrelativistic ground-state wave function and energy of the lithium atom is obtained in the Hylleraas basis set. The leading relativistic corrections,as represented by Breit-Pauli Hamiltonian, are obtained in fair agreement with the former results. The calculational method is based on the analytical evaluation of Hylleraas integrals with the help of recursion relations.
Matter wave interference pattern in the collision of bright solitons
International Nuclear Information System (INIS)
We investigate the dynamics of Bose-Einstein condensates in a quasi one-dimensional regime in a time-dependent trap and show analytically that it is possible to observe matter wave interference patterns in the intra-trap collision of two bright solitons by selectively tuning the trap frequency and scattering length.
Squeezing of Spin Waves in a Three-Dimensional Atomic Ensemble
Norris, Leigh; Baragiola, Ben; Montano, Enrique; Michelson, Pascal; Jessen, Poul; Deutsch, Ivan
2013-03-01
Spin squeezed states (SSS) have generated considerable interest for their potential applications in quantum metrology and quantum information processing. Many protocols for generating SSS in atomic gases rely on the Faraday interaction that creates entanglement between atoms through the coupling of the collective spin of the ensemble to polarization modes of an optical field. Most descriptions of this process rely on an idealized one-dimensional plane wave model of light-matter interactions that is not appropriate for describing a real system consisting of a cigar-shaped cold atomic cloud in dipole trap interacting with a probe laser beam. We provide a first principles three-dimensional model of squeezing via a quantum nondemolition measurement of the collective magnetization for an ensemble of atoms with hyperfine spin f. The model includes spin waves, diffraction, paraxial modes, and optical pumping, derived by a full master equation description. Including dissipative dynamics, we find the optimal ensemble geometry and input Gaussian beam parameters for generating spin squeezing. We also study the effect of enhancing the atom-light interface using internal hyperfine control of atoms with large spin f. Supported by NSF
New method for gravitational wave detection with atomic sensors.
Graham, Peter W; Hogan, Jason M; Kasevich, Mark A; Rajendran, Surjeet
2013-04-26
Laser frequency noise is a dominant noise background for the detection of gravitational waves using long-baseline optical interferometry. Amelioration of this noise requires near simultaneous strain measurements on more than one interferometer baseline, necessitating, for example, more than two satellites for a space-based detector or two interferometer arms for a ground-based detector. We describe a new detection strategy based on recent advances in optical atomic clocks and atom interferometry which can operate at long baselines and which is immune to laser frequency noise. Laser frequency noise is suppressed because the signal arises strictly from the light propagation time between two ensembles of atoms. This new class of sensor allows sensitive gravitational wave detection with only a single baseline. This approach also has practical applications in, for example, the development of ultrasensitive gravimeters and gravity gradiometers. PMID:23679702
Exact wave functions for atomic electron interacting with photon fields
Institute of Scientific and Technical Information of China (English)
Dong-Sheng Guo
2013-01-01
Many nonlinear quantum optical physics phenomena need more accurate wave functions and corresponding energy or quasienergy levels to account for. An analytic expression of wave functions with corresponding energy levels for an atomic electron interacting with a photon field is presented as an exact solution to the SchrSdinger-like equation involved with both atomic Coulomb interaction and electron-photon interaction. The solution is a natural generalization of the quantum-field Volkov states for an otherwise free electron interacting with a photon field. The solution shows that an N- level atom in light form stationary states without extra energy splitting in addition to the Floquet mechanism. The treatment developed here with computing codes can be conveniently transferred to quantum optics in classical-field version as research tools to benefit the whole physics community.
Safeguards and legal matters 1996. International Atomic Energy Agency publications
International Nuclear Information System (INIS)
This catalogue lists all currently valid sales publications of the International Atomic Energy Agency dealing with Safeguards and Legal Matters. Most publications are published in English. Proceedings of conferences, symposia and panels of experts may contain some papers in languages other than English (French, Russian or Spanish), but all of these papers have abstracts in English. It should be noted that prices of books are quoted in Austrian Schillings. The prices do not include local taxes and are subject to change without notice. All books in this catalogue are 16 x 24 cm, paper-bound, unless otherwise stated
Weak Nonlinear Matter Waves in a Trapped Spin-1 Condensates
Institute of Scientific and Technical Information of China (English)
CAI Hong-Qiang; YANG Shu-Rong; XUE Ju-Kui
2011-01-01
The dynamics of the weak nonlinear matter solitary waves in a spin-1 condensates with harmonic external potential are investigated analytically by a perturbation method. It is shown that, in the small amplitude limit, the dynamics of the solitary waves are governed by a variable-coefficient Korteweg-de Vries (KdV) equation. The reduction to the (KdV) equation may be useful to understand the dynamics of nonlinear matter waves in spinor BEGs. The analytical expressions for the evolution of soliton show that the small-amplitude vector solitons of the mixed types perform harmonic oscillations in the presence of the trap. Furthermore, the emitted radiation profiles and the soliton oscillation freauencv are also obtained.
Atom Interferometry for Fundamental Physics and Gravity Measurements in Space
Kohel, James M.
2012-01-01
Laser-cooled atoms are used as freefall test masses. The gravitational acceleration on atoms is measured by atom-wave interferometry. The fundamental concept behind atom interferometry is the quantum mechanical particle-wave duality. One can exploit the wave-like nature of atoms to construct an atom interferometer based on matter waves analogous to laser interferometers.
Matter-wave propagation in optical lattices: geometrical and flat-band effects
Metcalf, Mekena; Chern, Gia-Wei; Di Ventra, Massimiliano; Chien, Chih-Chun
2016-04-01
The geometry of optical lattices can be engineered, allowing the study of atomic transport along paths arranged in patterns that are otherwise difficult to probe in the solid state. A question feasible to atomic systems is related to the speed of matter-wave propagation as a function of the lattice geometry. To address this issue, we investigated, theoretically, the quantum transport of noninteracting and weakly-interacting ultracold fermionic atoms in several 2D optical lattice geometries. We find that the triangular lattice has a higher propagation velocity compared to the square lattice, and the cross-linked square lattice has an even faster propagation velocity. The increase results from the mixing of the momentum states which leads to different group velocities in quantum systems. Standard band theory provides an explanation and allows for a systematic way to search and design systems with controllable matter-wave propagation. Moreover, the presence of a flat band such as in a two-leg ladder geometry leads to a dynamical density discontinuity due to its localized atoms. Possible realizations of those dynamical phenomena are discussed.
Mean-Field Dynamics and Fisher Information in Matter Wave Interferometry
Haine, Simon A.
2016-06-01
There has been considerable recent interest in the mean-field dynamics of various atom-interferometry schemes designed for precision sensing. In the field of quantum metrology, the standard tools for evaluating metrological sensitivity are the classical and quantum Fisher information. In this Letter, we show how these tools can be adapted to evaluate the sensitivity when the behavior is dominated by mean-field dynamics. As an example, we compare the behavior of four recent theoretical proposals for gyroscopes based on matter-wave interference in toroidally trapped geometries. We show that while the quantum Fisher information increases at different rates for the various schemes considered, in all cases it is consistent with the well-known Sagnac phase shift after the matter waves have traversed a closed path. However, we argue that the relevant metric for quantifying interferometric sensitivity is the classical Fisher information, which can vary considerably between the schemes.
Mean-Field Dynamics and Fisher Information in Matter Wave Interferometry.
Haine, Simon A
2016-06-10
There has been considerable recent interest in the mean-field dynamics of various atom-interferometry schemes designed for precision sensing. In the field of quantum metrology, the standard tools for evaluating metrological sensitivity are the classical and quantum Fisher information. In this Letter, we show how these tools can be adapted to evaluate the sensitivity when the behavior is dominated by mean-field dynamics. As an example, we compare the behavior of four recent theoretical proposals for gyroscopes based on matter-wave interference in toroidally trapped geometries. We show that while the quantum Fisher information increases at different rates for the various schemes considered, in all cases it is consistent with the well-known Sagnac phase shift after the matter waves have traversed a closed path. However, we argue that the relevant metric for quantifying interferometric sensitivity is the classical Fisher information, which can vary considerably between the schemes. PMID:27341216
Average-Atom Model for X-ray Scattering from Warm Dense Matter
Johnson, W R; Cheng, K T
2012-01-01
A scheme for analyzing Thomson scattering of x-rays by warm dense matter, based on the average-atom model, is developed. Emphasis is given to x-ray scattering by bound electrons. Contributions to the scattered x-ray spectrum from elastic scattering by electrons moving with the ions and from inelastic scattering by free and bound electrons are evaluated using parameters (chemical potential, average ionic charge, free electron density, bound and continuum wave functions, and occupation numbers) taken from the average-atom model. The resulting scheme provides a relatively simple diagnostic for use in connection with x-ray scattering measurements. Applications are given to dense hydrogen, beryllium, aluminum, titanium, and tin plasmas. At high momentum transfer, contributions from inelastic scattering by bound electrons are dominant features of the scattered x-ray spectrum for aluminum, titanium, and tin.
New source for matter wave interferometry
International Nuclear Information System (INIS)
Full text: In order to explore the transition between the quantum and the classical world we investigate the possibility of seeing non-classical interference effects with big molecules. This requires new interferometer concepts but also efficient methods to bring neutral molecules into the gas phase and to detect them selectively and efficiently after the interference. Up to now all macromolecule interference experiments were using thermal sources. But for thermo-labile particles such as for instance biomolecules even weak heating can lead to fragmentation, so that a different method is needed. We have successfully implemented a jet-cooled laser desorption source in which the molecules are first desorbed from a surface in a nanosecond laser pulse and then injected into an adiabatically expanding cooling jet of noble gas atoms. We demonstrate the efficiency of our method for the amino acids tryptophan (204 u) and the polypeptide gramicidin(1900 u) and we shed some light on the challenges and chances for proteins such as insulin (5700 u). We show that translational temperatures as low as 15 K can be reached for amino acids. Techniques for volatizing large neutral molecules will be the basis for future quantum interferometry experiments, but they will also enable further studies in the domain of slowing, cooling and spectroscopy of macromolecules. (author)
Ultracold neutrons and the interaction of waves with moving matter
Frank, A. I.
2016-07-01
The present review is focused on the problem of interaction of neutron waves with moving matter. The validity of the 1/ v law for ultracold neutrons and the possibility to characterize the interaction of neutrons with matter using the effective potential were verified in the so-called null Fizeau experiments. A neutron wave in such experiments propagates through a flat sample that moves parallel to its edges. The observation of effects caused by this motion provides evidence that the concept of constant effective potential is not correct. The second part of the review deals with the prediction and the first observation of the accelerated matter effect (a change in the energy of neutrons in passing through a refractive sample that moves with an acceleration directed along or opposite the direction of neutron propagation). The characteristic features of this phenomenon in the case of birefringent material are considered. In conclusion, the problem of propagation of neutron waves in matter moving with giant acceleration is discussed.
Studies of Four Wave Mixing in a Cold Atomic Ensemble for Efficient Generation of Photon Pairs
Ferdinand, Andrew Richard; Luo, Xijie; Becerra, Francisco Elohim
2016-05-01
Photon pairs generated by spontaneous four-wave mixing (FWM) in atomic ensembles provide a natural path toward quantum light-matter interfaces due to their intrinsic compatibility with atomic quantum memories. We study the generation of light from a semi-classical FWM process in an elongated ensemble of cold cesium (Cs) atoms. We investigate the generation efficiency as a function of power, detuning, and polarization of the pump fields in the process. This study will allow us to determine the pump-field parameters in our system for the efficient generation of correlated photon pairs from a spontaneous FWM process. This work is supported by AFOSR Grant FA9550-14-1-0300.
Black Hole Window into p-Wave Dark Matter Annihilation.
Shelton, Jessie; Shapiro, Stuart L; Fields, Brian D
2015-12-01
We present a new method to measure or constrain p-wave-suppressed cross sections for dark matter (DM) annihilations inside the steep density spikes induced by supermassive black holes. We demonstrate that the high DM densities, together with the increased velocity dispersion, within such spikes combine to make thermal p-wave annihilation cross sections potentially visible in γ-ray observations of the Galactic center (GC). The resulting DM signal is a bright central point source with emission originating from DM annihilations in the absence of a detectable spatially extended signal from the halo. We define two simple reference theories of DM with a thermal p-wave annihilation cross section and establish new limits on the combined particle and astrophysical parameter space of these models, demonstrating that Fermi Large Area Telescope is currently sensitive to thermal p-wave DM over a wide range of possible scenarios for the DM distribution in the GC. PMID:26684108
Localized atomic basis set in the projector augmented wave method
DEFF Research Database (Denmark)
Larsen, Ask Hjorth; Vanin, Marco; Mortensen, Jens Jørgen;
2009-01-01
is tested by calculating atomization energies and equilibrium bulk properties of a variety of molecules and solids, comparing to the grid results. Finally, it is demonstrated how a grid-quality structure optimization can be performed with significantly reduced computational effort by switching......We present an implementation of localized atomic-orbital basis sets in the projector augmented wave (PAW) formalism within the density-functional theory. The implementation in the real-space GPAW code provides a complementary basis set to the accurate but computationally more demanding grid...
Search for Ultralight Scalar Dark Matter with Atomic Spectroscopy.
Van Tilburg, Ken; Leefer, Nathan; Bougas, Lykourgos; Budker, Dmitry
2015-07-01
We report new limits on ultralight scalar dark matter (DM) with dilatonlike couplings to photons that can induce oscillations in the fine-structure constant α. Atomic dysprosium exhibits an electronic structure with two nearly degenerate levels whose energy splitting is sensitive to changes in α. Spectroscopy data for two isotopes of dysprosium over a two-year span are analyzed for coherent oscillations with angular frequencies below 1 rad s-1. No signal consistent with a DM coupling is identified, leading to new constraints on dilatonlike photon couplings over a wide mass range. Under the assumption that the scalar field comprises all of the DM, our limits on the coupling exceed those from equivalence-principle tests by up to 4 orders of magnitude for masses below 3×10(-18) eV. Excess oscillatory power, inconsistent with fine-structure variation, is detected in a control channel, and is likely due to a systematic effect. Our atomic spectroscopy limits on DM are the first of their kind, and leave substantial room for improvement with state-of-the-art atomic clocks. PMID:26182090
Detecting quark matter in the early universe by gravitational waves
Schettler, Simon; Schaffner-Bielich, Jurgen
2011-01-01
For large baryochemical potential, strongly interacting matter might undergo a first order phase transition at temperatures T ~ 100-200 MeV. Within standard cosmology, however, the chemical potential is assumed to be very small leading to a crossover. We discuss implications of a first order QCD transition at high chemical potential being consistent with current observations. In this contribution we concentrate on effects on the gravitational wave spectrum. There are other interesting cosmological signals as a modification of the power spectrum of dark matter, the production of stellar black holes, and the seeds for the extragalactic magnetic fields which we briefly address also.
Gravitational wave detection with optical lattice atomic clocks
Kolkowitz, Shimon; Langellier, Nicholas; Lukin, Mikhail D; Walsworth, Ronald L; Ye, Jun
2016-01-01
We propose a space-based gravitational wave detector consisting of two spatially separated, drag-free satellites sharing ultra-stable optical laser light over a single baseline. Each satellite contains an optical lattice atomic clock, which serves as a sensitive, narrowband detector of the local frequency of the shared laser light. A synchronized two-clock comparison between the satellites will be sensitive to the effective Doppler shifts induced by incident gravitational waves (GWs) at a level competitive with other proposed space-based GW detectors, while providing complementary features. The detected signal is a differential frequency shift of the shared laser light due to the relative velocity of the satellites, rather than a phase shift arising from the relative satellite positions, and the detection window can be tuned through the control sequence applied to the atoms' internal states. This scheme enables the detection of GWs from continuous, spectrally narrow sources, such as compact binary inspirals, ...
Tully-Fisher Scalings and Boundary Conditions for Wave Dark Matter
Goetz, Andrew S.
2015-01-01
We investigate a theory of dark matter called wave dark matter, also known as scalar field dark matter (SFDM) and boson star dark matter or Bose-Einstein condensate (BEC) dark matter (also see axion dark matter), and its relation to the Tully-Fisher relation. We exhibit two boundary conditions that give rise to Tully-Fisher-like relations for spherically symmetric static wave dark matter halos: (BC1) Fixing a length scale at the outer edge of wave dark matter halos gives rise to a Tully-Fishe...
The wave impedance of an atomically thin crystal
Merano, Michele
2015-01-01
I propose an expression for the electromagnetic wave impedance of a two-dimensional atomic crystal, and I deduce the Fresnel coefficients in terms of this quantity. It is widely known that a two-dimensional crystal can absorb light, if its conductivity is different from zero. It is less emphasized that they can also store a certain amount of electromagnetic energy. The concept of impedance is useful to quantify this point.
Influence of conformational molecular dynamics on matter wave interferometry
Gring, Michael; Eibenberger, Sandra; Nimmrichter, Stefan; Berrada, Tarik; Arndt, Markus; Ulbricht, Hendrik; Hornberger, Klaus; Müri, Marcel; Mayor, Marcel; Böckmann, Marcus; Doltsinis, Nikos
2014-01-01
We investigate the influence of thermally activated internal molecular dynamics on the phase shifts of matter waves inside a molecule interferometer. While de Broglie physics generally describes only the center-of-mass motion of a quantum object, our experiment demonstrates that the translational quantum phase is sensitive to dynamic conformational state changes inside the diffracted molecules. The structural flexibility of tailor-made hot organic particles is sufficient to admit a mixture of strongly fluctuating dipole moments. These modify the electric susceptibility and through this the quantum interference pattern in the presence of an external electric field. Detailed molecular dynamics simulations combined with density functional theory allow us to quantify the time-dependent structural reconfigurations and to predict the ensemble-averaged square of the dipole moment which is found to be in good agreement with the interferometric result. The experiment thus opens a new perspective on matter wave interfe...
"Photonic" Cat States from Strongly Interacting Matter Waves.
Fischer, Uwe R; Kang, Myung-Kyun
2015-12-31
We consider ultracold quantum gases of scalar bosons residing in a coupling strength-density regime in which they constitute a twofold fragmented condensate trapped in a single well. It is shown that the corresponding quantum states are, in the appropriate Fock space basis, identical to the photon cat states familiar in quantum optics, which correspond to superpositions of coherent states of the light field with a phase difference of π. In marked distinction to photon cat states, however, the very existence of matter-wave cat states crucially depends on the many-body correlations of the constituent bosons. We consequently establish that the quadratures of the effective "photons," expressing the highly nonclassical nature of the macroscopic matter-wave superposition state, can be experimentally accessed by measuring the density-density correlations of the interacting quantum gas. PMID:26764977
Detecting quark matter in the early universe by gravitational waves
Schettler, Simon; Boeckel, Tillmann; Schaffner-Bielich, Jurgen
2011-01-01
For large baryochemical potential, strongly interacting matter might undergo a first order phase transition at temperatures T ~ 100-200 MeV. Within standard cosmology, however, the chemical potential is assumed to be very small leading to a crossover. We discuss implications of a first order QCD transition at high chemical potential being consistent with current observations. In this contribution we concentrate on effects on the gravitational wave spectrum. There are other interesting cosmolo...
Quantum interference of molecules -- probing the wave nature of matter
Venugopalan, Anu
2012-01-01
The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that el...
Peptides and proteins in matter wave interferometry: Challenges and prospects
Sezer, Ugur; Geyer, Philipp; Mairhofer, Lukas; Brand, Christian; Doerre, Nadine; Rodewald, Jonas; Schaetti, Jonas; Koehler, Valentin; Mayor, Marcel; Arndt, Markus
2016-05-01
Recent developments in matter wave physics suggest that quantum interferometry with biologically relevant nanomaterials is becoming feasible for amino acids, peptides, proteins and RNA/DNA strands. Quantum interference of biomolecules is interesting as it can mimic Schrödinger's cat states with molecules of high mass, elevated temperature and biological functionality. Additionally, the high internal complexity can give rise to a rich variety of couplings to the environment and new handles for quantitative tests of quantum decoherence. Finally, matter wave interferometers are highly sensitive force sensors and pave the way for quantum-assisted measurements of biomolecular properties in interaction with tailored or biomimetic environments. Recent interferometer concepts such as the Kapitza-Dirac-Talbot-Lau interferometer (KDTLI) or the Optical Time-domain Matter Wave interferometer (OTIMA) have already proven their potential for quantum optics in the mass range beyond 10000 amu and for metrology. Here we show our advances in quantum interferometry with vitamins and peptides and discuss methods of realizing cold, intense and sufficiently slow beams of synthetically tailored or hydrated polypeptides with promising properties for a new generation of quantum optics.
Matter Density and Relativistic Models of Wave Function Collapse
Bedingham, Daniel; Ghirardi, GianCarlo; Goldstein, Sheldon; Tumulka, Roderich; Zanghi, Nino
2011-01-01
Mathematical models for the stochastic evolution of wave functions that combine the unitary evolution according to the Schrodinger equation and the collapse postulate of quantum theory are well understood for non-relativistic quantum mechanics. Recently, there has been progress in making these models relativistic. But even with a fully relativistic law for the wave function evolution, a problem with relativity remains: Different Lorentz frames may yield conflicting values for the matter density at a space-time point. One solution to this problem is provided by Tumulka's "flash" model. Another solution is presented here. We propose a relativistic version of the law for the matter density function. According to our proposal, the matter density function at a space-time point x is obtained from the wave function psi on the past light cone of x by setting the i-th particle position in |psi|^2 equal to x, integrating over the other particle positions, and averaging over i. We show that the predictions that follow f...
Safeguards and legal matters 1994. International Atomic Energy Agency Publications
International Nuclear Information System (INIS)
This catalogue lists all sales publications of the International Atomic Energy Agency dealing with Safeguards and Legal Matters issued during the period 1970-1994. Most publications are published in English, through some are also available in French, Russian and Spanish. Proceedings of conferences, symposia and panels of experts may contain some papers in languages other than English (French, Russian or Spanish), but all of these papers have abstracts in English. If publications are also available in other languages than English, this is noted as C for Chinese, F for French, R for Russian and S for Spanish by the relevant ISBN number. It should be noted that prices of books are quoted in Austrian Schillings. The prices do not include local taxes and are subject to change without notice. All books in this catalogue are 16 x 24 cm, paper-bound, unless otherwise stated
Generating Schroedinger-cat states via scattering of quantum matter wave solitons
International Nuclear Information System (INIS)
The generation of spatial quantum superpositions via scattering solitons off a laser focus can be understood with a mathematically justified (for numeric investigations on the N-particle level). The motion of two attractively interacting atoms in an optical lattice is investigated in the presence of a scattering potential. The initial wavefunction can be prepared by using tightly bound exact two-particle eigenfunction for vanishing scattering potential. This allows to numerically simulate the dynamics in the generation of two-particle Schroedinger cat states using a scheme recently proposed for scattering of quantum matter wave solitons.
Position-momentum correlations in matter waves double-slit experiment
Neto, J. S. M.; Cabral, L. A.; da Paz, I. G.
2015-05-01
We present a treatment of the double-slit interference of matter-waves represented by Gaussian wavepackets. The interference pattern is modelled with Green's function propagator which emphasizes the coordinate correlations and phases. We explore the connection between phases and position-momentum correlations in the intensity, visibility and predictability of the wavepacket interference. This formulation will indicate some aspects that can be useful for theoretical and experimental treatment of particle, atom or molecule interferometry and can be discussed in introductory quantum mechanics courses.
Electron Rydberg wave packets in one-dimensional atoms
Indian Academy of Sciences (India)
Supriya Chatterjee; Amitava Choudhuri; Aparna Saha; B Talukdar
2010-09-01
An expression for the transition probability or form factor in one-dimensional Rydberg atom irradiated by short half-cycle pulse was constructed. In applicative contexts, our expression was found to be more useful than the corresponding result given by Landau and Lifshitz. Using the new expression for the form factor, the motion of a localized quantum wave packet was studied with particular emphasis on its revival and super-revival properties. Closed form analytical expressions were derived for expectation values of the position and momentum operators that characterized the widths of the position and momentum distributions. Transient phase-space localization of the wave packet produced by the application of a single impulsive kick was explicitly demonstrated. The undulation of the uncertainty product as a function of time was studied in order to visualize how the motion of the wave packet in its classical trajectory spreads throughout the orbit and the system becomes nonclassical. The process, however, repeats itself such that the atom undergoes a free evolution from a classical, to a nonclassical, and back to a classical state.
Noise Reduction in Magnetic Resonance Images using Wave Atom Shrinkage
Directory of Open Access Journals (Sweden)
J.Rajeesh, R.S.Moni, S.Palanikumar, T.Gopalakrishnan
2010-06-01
Full Text Available De-noising is always a challenging problem in magnetic resonance imaging andimportant for clinical diagnosis and computerized analysis, such as tissueclassification and segmentation. It is well known that the noise in magneticresonance imaging has a Rician distribution. Unlike additive Gaussian noise,Rician noise is signal dependent, and separating signal from noise is a difficulttask. An efficient method for enhancement of noisy magnetic resonance imageusing wave atom shrinkage is proposed. The reconstructed MRI data have highSignal to Noise Ratio (SNR compared to the curvelet and wavelet domain denoisingapproaches.
Discrete Wave-Packet Representation in Nuclear Matter Calculations
Müther, H; Kukulin, V I; Pomerantsev, V N
2016-01-01
The Lippmann-Schwinger equation for the nucleon-nucleon $t$-matrix as well as the corresponding Bethe-Goldstone equation to determine the Brueckner reaction matrix in nuclear matter are reformulated in terms of the resolvents for the total two-nucleon Hamiltonians defined in free space and in medium correspondingly. This allows to find solutions at many energies simultaneously by using the respective Hamiltonian matrix diagonalization in the stationary wave packet basis. Among other important advantages, this approach simplifies greatly the whole computation procedures both for coupled-channel $t$-matrix and the Brueckner reaction matrix. Therefore this principally novel scheme is expected to be especially useful for self-consistent nuclear matter calculations because it allows to accelerate in a high degree single-particle potential iterations. Furthermore the method provides direct access to the properties of possible two-nucleon bound states in the nuclear medium. The comparison between reaction matrices f...
Gravitational, shear and matter waves in Kantowski-Sachs cosmologies
Keresztes, Zoltán; Bradley, Michael; Dunsby, Peter K S; Gergely, László Á
2015-01-01
A general treatment of vorticity-free, perfect fluid perturbations of Kantowski-Sachs models with a positive cosmological constant are considered within the framework of the 1+1+2 covariant decomposition of spacetime. The dynamics is encompassed in six evolution equations for six harmonic coefficients, describing certain gravito-magnetic, kinematic and matter perturbations, and a set of algebraic expressions for the rest of the variables. The six equations further decouple into a set of four equations sourced by the perfect fluid, representing forced oscillations and two uncoupled damped oscillator equations. In the geometric optics approximation, the even and odd tensorial perturbations of the Weyl tensor evolve as gravitational waves on the anisotropic Kantowski-Sachs background, while the modes describing the shear and the matter density gradient are dephased by $\\pi /2$ and share the same speed of sound.
Chaotic matter shock wave of an open system
International Nuclear Information System (INIS)
We investigate a one-dimensional open Bose-Einstein condensate with attractive interaction, by considering the effect of feeding from nonequilibrium thermal cloud and applying the time-periodic inverted-harmonic potential. Using the direct perturbation method and the exact shock wave solution of the stationary Gross—Pitaevskii equation, we obtain the chaotic perturbed solution and the Melnikov chaotic regions. Based on the analytical and the numerical methods, the influence of the feeding strength on the chaotic motion is revealed. It is shown that the chaotic regions could be enlarged by reducing the feeding strength and the increase of feeding strength plays a role in suppressing chaos. In the case of “nonpropagated” shock wave with fixed boundary, the number of condensed atoms increases faster as the feeding strength increases. However, for the free boundary the metastable shock wave with fixed front density oscillates its front position and atomic number aperiodically, and their amplitudes decay with the increase of the feeding strength. (general)
Canuel, B; Amand, L; Bertoldi, A; Cormier, E; Fang, B; Gaffet, S; Geiger, R; Harms, J; Holleville, D; Landragin, A; Lefèvre, G; Lhermite, J; Mielec, N; Prevedelli, M; Riou, I; Bouyer, P
2016-01-01
The Matter-Wave laser Interferometer Gravitation Antenna, MIGA, will be a hybrid instrument composed of a network of atom interferometers horizontally aligned and interrogated by the resonant field of an optical cavity. This detector will provide measurements of sub Hertz variations of the gravitational strain tensor. MIGA will bring new methods for geophysics for the characterization of spatial and temporal variations of the local gravity field and will also be a demonstrator for future low frequency Gravitational Wave (GW) detections. MIGA will enable a better understanding of the coupling at low frequency between these different signals. The detector will be installed underground in Rustrel (FR), at the "Laboratoire Souterrain Bas Bruit" (LSBB), a facility with exceptionally low environmental noise and located far away from major sources of anthropogenic disturbances. We give in this paper an overview of the operating mode and status of the instrument before detailing simulations of the gravitational backg...
A universal matter-wave interferometer with optical ionization gratings in the time domain
Haslinger, Philipp; Geyer, Philipp; Rodewald, Jonas; Nimmrichter, Stefan; Arndt, Markus
2014-01-01
Matter-wave interferometry with atoms and molecules has attracted a rapidly growing interest over the past two decades, both in demonstrations of fundamental quantum phenomena and in quantum-enhanced precision measurements. Such experiments exploit the non-classical superposition of two or more position and momentum states which are coherently split and rejoined to interfere. Here, we present the experimental realization of a universal near-field interferometer built from three short-pulse single-photon ionization gratings. We observe quantum interference of fast molecular clusters, with a composite de Broglie wavelength as small as 275 fm. Optical ionization gratings are largely independent of the specific internal level structure and are therefore universally applicable to different kinds of nanoparticles, ranging from atoms to clusters, molecules and nanospheres. The interferometer is sensitive to fringe shifts as small as a few nanometers and yet robust against velocity-dependent phase shifts, since the g...
Quantum reflection of bright solitary matter waves from a narrow attractive potential
Marchant, A. L.; Billam, T. P.; Yu, M. M. H.; Rakonjac, A.; Helm, J. L.; Polo, J.; Weiss, C.; Gardiner, S. A.; Cornish, S. L.
2016-02-01
We report the observation of quantum reflection from a narrow attractive potential using bright solitary matter waves formed from a 85Rb Bose-Einstein condensate. We create the attractive potential using a tightly focused, red-detuned laser beam, and observe reflection of up to 25% of the atoms, along with the confinement of atoms at the position of the beam. We show that the observed reflected fraction is much larger than theoretical predictions for a simple Gaussian potential well. A more detailed model of bright soliton propagation, accounting for the generic presence of small subsidiary intensity maxima in the red-detuned beam, suggests that these small intensity maxima are the cause of this enhanced reflection.
Quantum reflection of bright solitary matter-waves from a narrow attractive potential
Marchant, A L; Yu, M M H; Rakonjac, A; Helm, J L; Polo, J; Weiss, C; Gardiner, S A; Cornish, S L
2015-01-01
We report the observation of quantum reflection from a narrow, attractive, potential using bright solitary matter-waves formed from a 85Rb Bose-Einstein condensate. We create narrow potentials using a tightly focused, red-detuned laser beam, and observe reflection of up to 25% of the atoms, along with the trapping of atoms at the position of the beam. We show that the observed reflected fraction is much larger than theoretical predictions for a narrow Gaussian potential well; a more detailed model of bright soliton propagation, accounting for the generic presence of small subsidiary intensity maxima in the red-detuned beam, suggests that these small intensity maxima are the cause of this enhanced reflection.
Spontaneous emission of a photon: wave packet structures and atom-photon entanglement
Fedorov, M. V.; Efremov, M. A.; Kazakov, A. E.; Chan, K W; Law, C. K.; Eberly, J. H.
2004-01-01
Spontaneous emission of a photon by an atom is described theoretically in three dimensions with the initial wave function of a finite-mass atom taken in the form of a finite-size wave packet. Recoil and wave-packet spreading are taken into account. The total atom-photon wave function is found in the momentum and coordinate representations as the solution of an initial-value problem. The atom-photon entanglement arising in such a process is shown to be closely related to the structure of atom ...
Hybrid Matter-Wave-Microwave Solitons Produced by the Local-Field Effect.
Qin, Jieli; Dong, Guangjiong; Malomed, Boris A
2015-07-10
It was recently found that the electric local-field effect (LFE) can lead to a strong coupling of atomic Bose-Einstein condensates (BECs) to off-resonant optical fields. We demonstrate that the magnetic LFE gives rise to a previously unexplored mechanism for coupling a (pseudo-) spinor BEC or fermion gas to microwaves (MWs). We present a theory for the magnetic LFE and find that it gives rise to a short-range attractive interaction between two components of the (pseudo) spinor, and a long-range interaction between them. The latter interaction, resulting from deformation of the magnetic field, is locally repulsive but globally attractive, in sharp contrast with its counterpart for the optical LFE, produced by phase modulation of the electric field. Our analytical results, confirmed by the numerical computations, show that the long-range interaction gives rise to modulational instability of the spatially uniform state, and it creates stable ground states in the form of hybrid matter-wave-microwave solitons (which seem like one-dimensional magnetic monopoles), with a size much smaller than the MW wavelength, even in the presence of arbitrarily strong contact intercomponent repulsion. The setting is somewhat similar to exciton-polaritonic condensates in semiconductor microcavities. The release of matter waves from the soliton may be used for the realization of an atom laser. The analysis also applies to molecular BECs with rotational states coupled by the electric MW field. PMID:26207469
Bouyer, P.
2015-12-01
Since its first demonstration in 1991, Atomic Interferometry (AI) has shown to be an extremely performing probe of inertial forces. More recently, AI has revealed sensitivities to acceleration or rotation competing with or even beating state-of-the art sensors based on other technologies. The high stability and accuracy of AI sensors relying on cold atoms is at the basis of several applications ranging from fundamental physics (e.g. tests of general relativity and measurements of fundamental constants), geophysics (gravimetry, gradiometry) and inertial navigation. We are currently building a large scale matter-wave detector which will open new applications in geoscience and fundamental physics. In contrast to standard AI based sensors, our matter-wave laser interferometer gravitation antenna (MIGA) exploits the superb seismic environment of a low noise underground laboratory. This new infrastructure is embedded into the LSBB underground laboratory, in France, ideally located away from major anthropogenic disturbances and benefitting from very low background noise. MIGA combines atom and laser interferometry techniques, manipulating an array of atomic ensembles distributed along the antenna to simultanously read out seismic effects, inertial effects and eventually the passage of a gravity wave. The first version uses a set of three atomic sensors placed along an optical cavity. The spatial resolution obtained with this configuration will enable the separation of the seismic, inertial and GW contributions. This technique will bring unprecedented sensitivities to gravity gradients variations and open new perspectives for sub Hertz gravity wave and geodesic detection. MIGA will provide measurements of gravity gradients variations limited only by the AI shot noise, which will allow sensitivities of about 10-13 s-2Hz-1/2@ 2Hz. This instrument will then be capable to spatially resolve 1 m3 of water a distances of about 100 m, which opens important potential applications
Photo-Ionization of Hydrogen Atom in a Circularly Polarized Standing Electromagnetic Wave
Institute of Scientific and Technical Information of China (English)
LIU Xiang-Tao; ZHANG Qi-Ren; WANG Wan-Zhang
2004-01-01
Applying time-independent non-perturbative formalism to the photo-ionization of hydrogen atom immersed in a strong circularly polarized standing electromagnetic wave, we calculate the shift of energy levels and the distortion of wave functions for the hydrogen atom, the ionization cross section induced by the standing wave, and the angular distribution of photoelectrons and obtain some interesting results.
Treatment of Ion-Atom Collisions Using a Partial-Wave Expansion of the Projectile Wavefunction
Wong, T. G.; Foster, M.; Colgan, J.; Madison, D. H.
2009-01-01
We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge…
Roura, Albert; Brill, Dieter R.; Hu, B. L.; Misner, Charles W.; Phillips, William D.
2004-01-01
We show that a recent claim that matter wave interferometers have a much higher sensitivity than laser interferometers for a comparable physical setup is unfounded. We point out where the mistake in the earlier analysis is made. We also disprove the claim that only a description based on the geodesic deviation equation can produce the correct physical result. The equations for the quantum dynamics of non-relativistic massive particles in a linearly perturbed spacetime derived here are useful ...
Jeans Analysis for Dwarf Spheroidal Galaxies in Wave Dark Matter
Chen, Shu-Rong; Chiueh, Tzihong
2016-01-01
Observations suggest that dwarf spheroidal (dSph) galaxies exhibit large constant-density cores in the centers, which can hardly be explained by dissipationless cold dark matter simulations. Wave dark matter (${\\psi {\\rm DM}}$), characterized by a single parameter, the dark matter particle mass $m_{\\psi}$, predicts a central soliton core in every galaxy arising from quantum pressure against gravity. Here we apply Jeans analysis to the kinematic data of eight classical dSphs so as to constrain $m_{\\psi}$, and obtain $m_{\\psi}=1.18_{-0.24}^{+0.28}\\times10^{-22}{\\,\\rm eV}$ and $m_{\\psi}=1.79_{-0.33}^{+0.35}\\times10^{-22}{\\,\\rm eV}~(2\\sigma)$ using the observational data sets of Walker et al. (2007) and Walker et al. (2009b), respectively. We show that the estimate of $m_{\\psi}$ is sensitive to the dSphs kinematic data sets and is robust to various models of stellar density profile. We also consider multiple stellar subpopulations in dSphs and find consistent results. This mass range of $m_{\\psi}$ is in good agre...
Approximate relativistic corrections to atomic radial wave functions
Energy Technology Data Exchange (ETDEWEB)
Cowan, R.D.; Griffin, D.C.
1976-10-01
The mass-velocity and Darwin terms of the one-electron-atom Pauli equation have been added to the Hartree-Fock differential equations by using the HX formula to calculate a local central field potential for use in these terms. Introduction of the quantum number j is avoided by omitting the spin-orbit term of the Pauli equation. The major relativistic effects, both direct and indirect, are thereby incorporated into the wave functions, while allowing retention of the commonly used nonrelativistic formulation of energy level calculations. The improvement afforded in calculated total binding energies, excitation energies, spin-orbit parameters, and expectation values of r/sub m/ is comparable with that provided by fully relativistic Dirac-Hartree-Fock calculations. (AIP)
Coexistence of four-wave, six-wave and eight-wave mixing processes in multi-dressed atomic systems
Energy Technology Data Exchange (ETDEWEB)
Zhang Yanpeng; Anderson, Blake; Xiao Min [Department of Physics, University of Arkansas, Fayetteville, AR 72701 (United States)], E-mail: ypzhang@mail.xjtu.edu.cn, E-mail: mxiao@uark.edu
2008-02-28
Two doubly dressing (parallel and nested processes) schemes are considered which generate co-existing four-wave mixing (FWM), six-wave mixing (SWM) and eight-wave mixing (EWM) processes in an open five-level atomic system. The coherent interaction between two dressing processes in nested type is much stronger than that in parallel type. The singly enhanced SWM and dually enhanced FWM channels can be opened at the same time. Such dramatic enhancements in high-order nonlinear optical processes result from the constructive interactions of double dark resonances. The giant third-, fifth- and seventh-order nonlinear responses with different signs can be obtained by using the coherent phase controls of the polarization beats between the FWM, SWM and EWM signa0008.
Spherically Symmetric Static States of Wave Dark Matter
Parry, Alan R
2013-01-01
We explore spherically symmetric solutions to the Einstein-Klein-Gordon equations, the defining equations of wave dark matter, where the scalar field is of the form f(t,r) = exp(i\\omega t)F(r) for some constant \\omega\\ in R and complex-valued function F(r). We show that the corresponding metric is static if and only if F(r) = h(r)exp(ia) for some constant a in R and real-valued function h(r). We describe the behavior of the resulting solutions, which are called spherically symmetric static states. We also describe how, in the low field limit, the parameters defining these static states are related and show that these relationships imply important properties of the static states.
Miniature inhalation therapy platform using surface acoustic wave microfluidic atomization.
Qi, Aisha; Friend, James R; Yeo, Leslie Y; Morton, David A V; McIntosh, Michelle P; Spiccia, Leone
2009-08-01
Pulmonary drug administration requires direct delivery of drug formulations into the lower pulmonary tract and alveoli of the lung in the form of inhaled particles or droplets, providing a distinct advantage over other methods for the treatment of respiratory diseases: the drug can be delivered directly to the site of inflammation, thus reducing the need for systemic exposure and the possibility of adverse effects. However, it is difficult to produce droplets of a drug solution within a narrow monodisperse size range (1-10 microm) needed for deposition in the lower pulmonary tract and alveoli. Here, we demonstrate the use of surface acoustic wave microfluidic atomization as an efficient means to generate appropriate aerosols containing a model drug, the short-acting beta2 agonist salbutamol, for the treatment of asthma. The mean aerosol diameter produced, 2.84+/-0.14 microm, lies well within the optimum size range, confirmed by a twin-stage impinger lung model, demonstrating that approximately 70 to 80% of the drug supplied to the atomizer is deposited within the lung. Our preliminary study explores how to control the aerosol diameter and lung delivery efficiency through the surface tension, viscosity, and input power, and also indicates which factors are irrelevant-like the fluid density. Even over a modest power range of 1-1.5 W, SAW atomization provides a viable and efficient generic nebulization platform for the delivery of drugs via the pulmonary route for the treatment of various diseases. The control offered over the aerosol size, low power requirements, high delivery efficiency, and the miniaturization of the system together suggest the proposed platform represents an attractive alternative to current nebulizers compatible with microfluidic technologies. PMID:19606295
Non-locality and destructive interference of matter waves
International Nuclear Information System (INIS)
Quantum mechanics with massive particles becomes an important tool for fundamental research and applied science since many previously named 'Gedanken' experiments become feasible. Neutrons are massive particles which couple to gravitational, nuclear and electro-magnetic interactions and they are sensitive to topological effects as well. Therefore they are proper tools for testing quantum mechanics where several previously named 'hidden' parameters become measurable. Widely separated coherent beams can be produced by means of perfect crystal interferometers and they can be influenced individually. Spinor symmetry, spin superposition and quantum beat effect experiments have been performed and topological phases have been observed. Recent experiments related to the decoherence problem have shown that interference effects can be revived even when the overall interference pattern seems to be incoherent. All retrieval processes involve inherently unavoidable losses which stem partly from the theory itself and partly from an imperfect environment. Related post-selection experiments shed a new light on questions of quantum non-locality and support the request for more complete quantum measurements in the future. A more rational explanation of non-locality effects may be obtained when the plane wave components outside the wave packets are included in the discussion. This can also help to discuss entanglement and contextuality effects in a new light. In all quantum experiments more information can be extracted by more complete quantum experiments which will be important in the future to get a better understanding of quantum physics. An example may be the consideration of the Compton frequency and of proper time effects of matter waves.
Matter, dark matter and gravitational waves from a GUT-scale U(1) phase transition
International Nuclear Information System (INIS)
The cosmological realization of the spontaneous breaking of B-L, the difference of baryon and lepton number, can generate the initial conditions for the hot early universe. In particular, we show that entropy, dark matter and a matter-antimatter asymmetry can be produced in accordance with current observations. If B-L is broken at the grand unification scale, F-term hybrid inflation can be realized in the false vacuum of unbroken B-L. The phase transition at the end of inflation, governed by tachyonic preheating, spontaneously breaks the U(1)B-L symmetry and sets the initial conditions for the following perturbative reheating phase. We provide a detailed, time-resolved picture of the reheating process. The competition of cosmic expansion and entropy production leads to an intermediate plateau of constant temperature, which controls both the generated lepton asymmetry and the dark matter abundance. This enables us to establish relations between the neutrino and superparticle mass spectrum, rendering this mechanism testable. Moreover, we calculate the entire gravitational wave spectrum for this setup. This yields a promising possibility to probe cosmological B - L breaking with forthcoming gravitational wave detectors such as eLISA, advanced LIGO and BBO/DECIGO. The largest contribution is obtained from cosmic strings which is, for typical parameter values, at least eight orders of magnitude higher then the contribution from inflation. Finally, we study the possibility of realizing hybrid inflation in a superconformal framework. We find that superconformal D-term inflation is an interesting possibility generically leading to a two-field inflation model, but in its simplest version disfavoured by the recently published Planck data.
Matter, dark matter and gravitational waves from a GUT-scale U(1) phase transition
Energy Technology Data Exchange (ETDEWEB)
Domcke, Valerie
2013-09-15
The cosmological realization of the spontaneous breaking of B-L, the difference of baryon and lepton number, can generate the initial conditions for the hot early universe. In particular, we show that entropy, dark matter and a matter-antimatter asymmetry can be produced in accordance with current observations. If B-L is broken at the grand unification scale, F-term hybrid inflation can be realized in the false vacuum of unbroken B-L. The phase transition at the end of inflation, governed by tachyonic preheating, spontaneously breaks the U(1){sub B-L} symmetry and sets the initial conditions for the following perturbative reheating phase. We provide a detailed, time-resolved picture of the reheating process. The competition of cosmic expansion and entropy production leads to an intermediate plateau of constant temperature, which controls both the generated lepton asymmetry and the dark matter abundance. This enables us to establish relations between the neutrino and superparticle mass spectrum, rendering this mechanism testable. Moreover, we calculate the entire gravitational wave spectrum for this setup. This yields a promising possibility to probe cosmological B - L breaking with forthcoming gravitational wave detectors such as eLISA, advanced LIGO and BBO/DECIGO. The largest contribution is obtained from cosmic strings which is, for typical parameter values, at least eight orders of magnitude higher then the contribution from inflation. Finally, we study the possibility of realizing hybrid inflation in a superconformal framework. We find that superconformal D-term inflation is an interesting possibility generically leading to a two-field inflation model, but in its simplest version disfavoured by the recently published Planck data.
Institute of Scientific and Technical Information of China (English)
Li Yu-Qing; Ma Jie; Wu Ji-Zhou; Zhang Yi-Chi; Zhao Yan-Ting; Wang Li-Rong; Xiao Lian-Tuan; Jia Suo-Tang
2012-01-01
We report on the observation of enhanced high-order partial wave scattering from atom-atom interaction via changing the temperature of a magneto-optical trap in the process of photoassociation. The high-order scattering partial wave is directly manifested through the large signal amplitude of the rovibrational resonance levels of trap-loss spectroscopy from photoassociation.
Slowly moving matter-wave gap soliton propagation in weak random nonlinear potential
Institute of Scientific and Technical Information of China (English)
Zhang Ming-Rui; Zhang Yong-Liang; Jiang Xun-Ya; Zi Jian
2008-01-01
We systematically investigate the motion of slowly moving matter-wave gap solitons in a nonlinear potential, produced by the weak random spatial variation of the atomic scattering length. With the weak randomness, we construct an effective-particle theory to study the motion of gap solitons. Based on the effective-particle theory, the effect of the randomness on gap solitous is obtained, and the motion of gap solitons is finally solved. Moreover, the analytic results for the general behaviours of gap soliton motion, such as the ensemble-average speed and the reflection probability depending on the weak randomness are obtained. We find that with the increase of the random strength the ensemble-average speed of gap solitons decreases slowly where the reduction is proportional to the variance of the weak randomness, and the reflection probability becomes larger. The theoretical results are in good agreement with the numerical simulations based on the Gross-Pitaevskii equation.
Exploring the stability and dynamics of dipolar matter-wave dark solitons
Edmonds, M. J.; Bland, T.; O'Dell, D. H. J.; Parker, N. G.
2016-06-01
We study the stability, form, and interaction of single and multiple dark solitons in quasi-one-dimensional dipolar Bose-Einstein condensates. The solitons are found numerically as stationary solutions in the moving frame of a nonlocal Gross Pitaevskii equation and characterized as a function of the key experimental parameters, namely the ratio of the dipolar atomic interactions to the van der Waals interactions, the polarization angle, and the condensate width. The solutions and their integrals of motion are strongly affected by the phonon and roton instabilities of the system. Dipolar matter-wave dark solitons propagate without dispersion and collide elastically away from these instabilities, with the dipolar interactions contributing an additional repulsion or attraction to the soliton-soliton interaction. However, close to the instabilities, the collisions are weakly dissipative.
Orbital dependent functionals: An atom projector augmented wave method implementation
Xu, Xiao
This thesis explores the formulation and numerical implementation of orbital dependent exchange-correlation functionals within electronic structure calculations. These orbital-dependent exchange-correlation functionals have recently received renewed attention as a means to improve the physical representation of electron interactions within electronic structure calculations. In particular, electron self-interaction terms can be avoided. In this thesis, an orbital-dependent functional is considered in the context of Hartree-Fock (HF) theory as well as the Optimized Effective Potential (OEP) method and the approximate OEP method developed by Krieger, Li, and Iafrate, known as the KLI approximation. In this thesis, the Fock exchange term is used as a simple well-defined example of an orbital-dependent functional. The Projected Augmented Wave (PAW) method developed by P. E. Blochl has proven to be accurate and efficient for electronic structure calculations for local and semi-local functions because of its accurate evaluation of interaction integrals by controlling multiple moments. We have extended the PAW method to treat orbital-dependent functionals in Hartree-Fock theory and the Optimized Effective Potential method, particularly in the KLI approximation. In the course of study we develop a frozen-core orbital approximation that accurately treats the core electron contributions for above three methods. The main part of the thesis focuses on the treatment of spherical atoms. We have investigated the behavior of PAW-Hartree Fock and PAW-KLI basis, projector, and pseudopotential functions for several elements throughout the periodic table. We have also extended the formalism to the treatment of solids in a plane wave basis and implemented PWPAW-KLI code, which will appear in future publications.
Gravitational Wave Detection with Single-Laser Atom Interferometers
Yu, Nan; Tinto, Massimo
2011-01-01
A new design for a broadband detector of gravitational radiation relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser are used for operating the two atom interferometers. The innovation here involves the fact that the atoms in the atom interferometers are not only considered as perfect test masses, but also as highly stable clocks. Atomic coherence is intrinsically stable, and can be many orders of magnitude more stable than a laser.
Stadnik, Yevgeny V; Flambaum, Victor V; Dzuba, Vladimir A
2015-01-01
We propose to search for scalar dark matter via its effects on the electromagnetic fine-structure constant and particle masses. Scalar dark matter that forms an oscillating classical field produces `slow' linear-in-time drifts and oscillating variations of the fundamental constants, while scalar dark matter that forms topological defects produces transient-in-time variations of the constants of Nature. These variations can be sought for with atomic clock, laser interferometer and pulsar timing measurements. Atomic spectroscopy and Big Bang nucleosynthesis measurements already give improved bounds on the quadratic interaction parameters of scalar dark matter with the photon, electron, and light quarks by up to 15 orders of magnitude, while Big Bang nucleosynthesis measurements provide the first such constraints on the interaction parameters of scalar dark matter with the massive vector bosons.
Stadnik, Y V
2015-01-01
We present an overview of recent developments in the detection of light bosonic dark matter, including axion, pseudoscalar axion-like and scalar dark matter, which form either a coherently oscillating classical field or topological defects (solitons). We emphasise new high-precision laboratory and astrophysical measurements, in which the sought effects are linear in the underlying interaction strength between dark matter and ordinary matter, in contrast to traditional detection schemes for dark matter, where the effects are quadratic or higher order in the underlying interaction parameters and are extremely small. New terrestrial experiments include measurements with atomic clocks, spectroscopy, atomic and solid-state magnetometry, torsion pendula, ultracold neutrons, and laser interferometry. New astrophysical observations include pulsar timing, cosmic radiation lensing, Big Bang nucleosynthesis and cosmic microwave background measurements. We also discuss various recently proposed mechanisms for the inducti...
Coupled matter-wave solitons in optical lattices
International Nuclear Information System (INIS)
We make use of a potential model to study the dynamics of two coupled matter-wave or Bose-Einstein condensate (BEC) solitons loaded in optical lattices. With separate attention to linear and nonlinear lattices we find some remarkable differences for response of the system to effects of these lattices. As opposed to the case of linear optical lattice (LOL), the nonlinear lattice (NOL) can be used to control the mutual interaction between the two solitons. For a given lattice wave number k, the effective potentials in which the two solitons move are such that the well (Veff(NOL)), resulting from the juxtaposition of soliton interaction and nonlinear lattice potential, is deeper than the corresponding well Veff(LOL). But these effective potentials have opposite k dependence in the sense that the depth of Veff(LOL) increases as k increases and that of Veff(NOL) decreases for higher k values. We verify that the effectiveness of optical lattices to regulate the motion of the coupled solitons depends sensitively on the initial locations of the motionless solitons as well as values of the lattice wave number. For both LOL and NOL the two solitons meet each other due to mutual interaction if their initial locations are taken within the potential wells with the difference that the solitons in the NOL approach each other rather rapidly and take roughly half the time to meet as compared with the time needed for such coalescence in the LOL. In the NOL, the soliton profiles can move freely and respond to the lattice periodicity when the separation between their initial locations are as twice as that needed for a similar free movement in the LOL. We observe that, in both cases, slow tuning of the optical lattices by varying k with respect to a time parameter τ drags the oscillatory solitons apart to take them to different locations. In our potential model the oscillatory solitons appear to propagate undistorted. But a fully numerical calculation indicates that during evolution
Coupled matter-wave solitons in optical lattices
Golam Ali, Sk; Talukdar, B.
2009-06-01
We make use of a potential model to study the dynamics of two coupled matter-wave or Bose-Einstein condensate (BEC) solitons loaded in optical lattices. With separate attention to linear and nonlinear lattices we find some remarkable differences for response of the system to effects of these lattices. As opposed to the case of linear optical lattice (LOL), the nonlinear lattice (NOL) can be used to control the mutual interaction between the two solitons. For a given lattice wave number k, the effective potentials in which the two solitons move are such that the well (Veff(NOL)), resulting from the juxtaposition of soliton interaction and nonlinear lattice potential, is deeper than the corresponding well Veff(LOL). But these effective potentials have opposite k dependence in the sense that the depth of Veff(LOL) increases as k increases and that of Veff(NOL) decreases for higher k values. We verify that the effectiveness of optical lattices to regulate the motion of the coupled solitons depends sensitively on the initial locations of the motionless solitons as well as values of the lattice wave number. For both LOL and NOL the two solitons meet each other due to mutual interaction if their initial locations are taken within the potential wells with the difference that the solitons in the NOL approach each other rather rapidly and take roughly half the time to meet as compared with the time needed for such coalescence in the LOL. In the NOL, the soliton profiles can move freely and respond to the lattice periodicity when the separation between their initial locations are as twice as that needed for a similar free movement in the LOL. We observe that, in both cases, slow tuning of the optical lattices by varying k with respect to a time parameter τ drags the oscillatory solitons apart to take them to different locations. In our potential model the oscillatory solitons appear to propagate undistorted. But a fully numerical calculation indicates that during evolution
Directing Matter: Toward Atomic-Scale 3D Nanofabrication.
Jesse, Stephen; Borisevich, Albina Y; Fowlkes, Jason D; Lupini, Andrew R; Rack, Philip D; Unocic, Raymond R; Sumpter, Bobby G; Kalinin, Sergei V; Belianinov, Alex; Ovchinnikova, Olga S
2016-06-28
Enabling memristive, neuromorphic, and quantum-based computing as well as efficient mainstream energy storage and conversion technologies requires the next generation of materials customized at the atomic scale. This requires full control of atomic arrangement and bonding in three dimensions. The last two decades witnessed substantial industrial, academic, and government research efforts directed toward this goal through various lithographies and scanning-probe-based methods. These technologies emphasize 2D surface structures, with some limited 3D capability. Recently, a range of focused electron- and ion-based methods have demonstrated compelling alternative pathways to achieving atomically precise manufacturing of 3D structures in solids, liquids, and at interfaces. Electron and ion microscopies offer a platform that can simultaneously observe dynamic and static structures at the nano- and atomic scales and also induce structural rearrangements and chemical transformation. The addition of predictive modeling or rapid image analytics and feedback enables guiding these in a controlled manner. Here, we review the recent results that used focused electron and ion beams to create free-standing nanoscale 3D structures, radiolysis, and the fabrication potential with liquid precursors, epitaxial crystallization of amorphous oxides with atomic layer precision, as well as visualization and control of individual dopant motion within a 3D crystal lattice. These works lay the foundation for approaches to directing nanoscale level architectures and offer a potential roadmap to full 3D atomic control in materials. In this paper, we lay out the gaps that currently constrain the processing range of these platforms, reflect on indirect requirements, such as the integration of large-scale data analysis with theory, and discuss future prospects of these technologies. PMID:27183171
Cooperatively enhanced light transmission in cold atomic matter
Kemp, Kasie; Havey, M D; Sokolov, I M; Kupriyanov, D V
2014-01-01
We report enhanced transmission in measurements of the spectral dependence of forward light scattering by a high-density and cold ensemble of 87Rb atoms. This phenomenon, which is a result of dipole-dipole interaction induced cooperative light scattering in the atomic sample, implies a significant departure from the traditional density dependence of the transmitted light as embodied in the Beer-Lambert Law. Absolute values of the density-dependent forward light scattering cross-section are extracted from the measurements.
S-wave and p-wave scattering in a cold gas of Na and Rb atoms
Ouerdane, H
2008-01-01
Using improved experimentally based $X{}^1\\Sigma^+$ and $a{}^3\\Sigma^+$ molecular potentials of NaRb, published recently by Pashov {\\it et al.} [Phys. Rev. A {\\bf 72}, 062505 (2005)], we apply the variable phase method to compute new data for low energy scattering of $^{23}$Na atoms by $^{85}$Rb atoms and $^{87}$Rb atoms. These are scattering lengths and volumes, numbers of bound states and effective ranges. From an analysis of the contributions of s-wave and p-wave scatterings to the elastic cross section we estimate temperatures below which only s-wave scattering is dominant. We supply evidence for the existence of a near zero energy p-wave bound state supported by the singlet molecular potential.
Theory of light-matter interactions in cascade and diamond type atomic ensembles
Jen, Hsiang-Hua
2011-01-01
In this thesis, we investigate the quantum mechanical interaction of light with matter in the form of a gas of ultracold atoms: the atomic ensemble. We present a theoretical analysis of two problems, which involve the interaction of quantized electromagnetic fields (called signal and idler) with the atomic ensemble (i) cascade two-photon emission in an atomic ladder configuration, and (ii) photon frequency conversion in an atomic diamond configuration. The motivation of these studies comes from potential applications in long-distance quantum communication where it is desirable to generate quantum correlations between telecommunication wavelength light fields and ground level atomic coherences. We develop a theory of correlated signal-idler pair correlation. The analysis is complicated by the possible generation of multiple excitations in the atomic ensemble. An analytical treatment is given in the limit of a single excitation assuming adiabatic laser excitations. The analysis predicts superradiant timescales ...
Atom Interferometry for detection of Gravity Waves-a Project
National Aeronautics and Space Administration — Atom interferometers are more sensitive to inertial effects. This is because atoms in their inertial frame are ideal test masses for detection of gravity effects...
Gravitational wave detection with single-laser atom interferometers
Yu, Nan; Tinto, Massimo
2010-01-01
We present a new general design approach of a broad-band detector of gravitational radiation that relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser will be used for operating the two atom interferometers. We consider atoms in the atom interferometers not only as perfect inertial reference sensors, but also as highly stable clocks. Atomic coherence is intrinsically stable and can be many orders of magnitude more stable than a laser. The un...
Dark matter searches using gravitational wave bar detectors: Quark nuggets and newtorites
Bassan, M.; Coccia, E.; D'Antonio, S.; Fafone, V.; Giordano, G.; Marini, A.; Minenkov, Y.; Modena, I.; Pallottino, G. V.; Pizzella, G.; Rocchi, A.; Ronga, F.; Visco, M.
2016-05-01
Many experiments have searched for supersymmetric WIMP dark matter, with null results. This may suggest to look for more exotic possibilities, for example compact ultra-dense quark nuggets, widely discussed in literature with several different names. Nuclearites are an example of candidate compact objects with atomic size cross section. After a short discussion on nuclearites, the result of a nuclearite search with the gravitational wave bar detectors Nautilus and Explorer is reported. The geometrical acceptance of the bar detectors is 19.5 m2 sr, that is smaller than that of other detectors used for similar searches. However, the detection mechanism is completely different and is more straightforward than in other detectors. The experimental limits we obtain are of interest because, for nuclearites of mass less than 10-5 g, we find a flux smaller than that one predicted considering nuclearites as dark matter candidates. Particles with gravitational only interactions (newtorites) are another example. In this case the sensitivity is quite poor and a short discussion is reported on possible improvements.
Study of Atomization of a Water Jet by High-Intensity Aerial Ultrasonic Waves
Ito, Youichi
2001-05-01
An experimental study has been carried out on the atomization of a water jet by aerially radiating it with high-intensity ultrasonic waves. A sound source that enables the linear generation of high-intensity aerial ultrasonic waves (frequency: approximately 20 kHz) is combined with a cylindrical reflection plate in order to create a standing-wave sound field. An attempt has been made to atomize a water jet of 1 mm diameter by passing it through the above sound field at a velocity of approximately 30 m/s. It has been clarified that nodes of sound pressure in the standing-wave sound field are effective for the atomization of a water jet. In addition, the atomizing phenomenon of a water jet has been observed precisely. The relation between the intensity of sound waves required for atomization and the radiation duration has also been clarified. Even the radiation of sound waves for only 2 ms atomizes water. This suggests that a very fast water jet at 300-500 m/s might be atomized.
Dynamics and Matter-Wave Solitons in Bose-Einstein Condensates with Two- and Three-Body Interactions
Directory of Open Access Journals (Sweden)
Jing Chen
2014-01-01
Full Text Available By means of similarity transformation, this paper proposes the matter-wave soliton solutions and dynamics of the variable coefficient cubic-quintic nonlinear Schrödinger equation arising from Bose-Einstein condensates with time-dependent two- and three-body interactions. It is found that, under the effect of time-dependent two- and three-body interaction and harmonic potential with time-dependent frequency, the density of atom condensates will gradually diminish and finally collapse.
Institute of Scientific and Technical Information of China (English)
宣恒农; 左苗
2011-01-01
We present three families of exact matter-wave soliton solutions for an effective one-dimension two- component Bose-Einstein condensates （BECs） with tunable interactions, harmonic potential and gain or loss term. We investigate the dynamics of bright-bright solitons, bright-dark solitons and dark-dark solitons for the time-dependent expulsive harmonic trap potential, periodically modulated harmonic trap potential, and kinklike modulated harmonic trap potential. Through the Feshbach resonance, these dynamics can be realized in experiments by suitable control of time-dependent trap parameters, atomic interactions, and interaction with thermal cloud.
Electron Scattering From Atoms, Molecules, Nuclei, and Bulk Matter
Whelan, Colm T
2005-01-01
Topics that are covered include electron scattering in the scanning TEM; basic theory of inelastic electron imaging; study of confined atoms by electron excitation; helium bubbles created in extreme pressure with application to nuclear safety; lithium ion implantation; electron and positron scattering from clusters; electron scattering from physi- and chemi-absorbed molecules on surfaces; coincidence studies; electron scattering from biological molecules; electron spectroscopy as a tool for environmental science; electron scattering in the presence of intense fields; electron scattering from astrophysical molecules; electon interatctions an detection of x-ray radiation.
Foot, Christopher J
2007-01-01
This text will thoroughly update the existing literature on atomic physics. Intended to accompany an advanced undergraduate course in atomic physics, the book will lead the students up to the latest advances and the applications to Bose-Einstein Condensation of atoms, matter-wave inter-ferometry and quantum computing with trapped ions. The elementary atomic physics covered in the early chapters should be accessible to undergraduates when they are first introduced to the subject. To complement. the usual quantum mechanical treatment of atomic structure the book strongly emphasizes the experimen
Improved limits on interactions of low-mass spin-0 dark matter from atomic clock spectroscopy
Stadnik, Y. V.; Flambaum, V. V.
2016-01-01
Low-mass (sub-eV) spin-0 dark matter particles, which form a coherently oscillating classical field $\\phi = \\phi_0 \\cos(m_\\phi t)$, can induce oscillating variations in the fundamental constants through their interactions with the Standard Model sector. We calculate the effects of such possible interactions, which may include the linear interaction of $\\phi$ with the Higgs boson, on atomic and molecular transitions. Using recent atomic clock spectroscopy measurements, we derive new limits on ...
Using time reversal symmetry for sensitive incoherent matter-wave Sagnac interferometry
Japha, Y.; Arzouan, O.; Avishai, Y.; Folman, R.
2007-01-01
We present a theory of the transmission of incoherent guided matter-waves through Sagnac interferometers. Interferometer configurations with only one input and one output port have a property similar to the phase rigidity observed in the transmission through Aharonov-Bohm interferometers in coherent mesoscopic electronics. This property is connected to the existence of counterpropagating paths of equal length and enables the operation of such matter-wave interferometers with incoherent source...
Wave Mechanics of a Two Wire Atomic Beamsplitter
Bortolotti, Daniele C. E.; Bohn, John L.
2003-01-01
We consider the problem of an atomic beam propagating quantum mechanically through an atom beam splitter. Casting the problem in an adiabatic representation (in the spirit of the Born-Oppenheimer approximation in molecular physics) sheds light on explicit effects due to non-adiabatic passage of the atoms through the splitter region. We are thus able to probe the fully three dimensional structure of the beam splitter, gathering quantitative information about mode-mixing, splitting ratios,and r...
Wave Mechanics of a Two Wire Atomic Beamsplitter
Bortolotti, D C E; Bortolotti, Daniele C. E.; Bohn, John L.
2004-01-01
We consider the problem of an atomic beam propagating quantum mechanically through an atom beam splitter. Casting the problem in an adiabatic representation (in the spirit of the Born-Oppenheimer approximation in molecular physics) sheds light on explicit effects due to non-adiabatic passage of the atoms through the splitter region. We are thus able to probe the fully three dimensional structure of the beam splitter, gathering quantitative information about mode-mixing, splitting ratios,and reflection and transmission probabilities.
Wave mechanics of a two-wire atomic beam splitter
International Nuclear Information System (INIS)
We consider the problem of an atomic beam propagating quantum mechanically through an atom beam splitter. Casting the problem in an adiabatic representation (in the spirit of the Born-Oppenheimer approximation in molecular physics) sheds light on explicit effects due to nonadiabatic passage of the atoms through the splitter region. We are thus able to probe the fully three-dimensional structure of the beam splitter, gathering quantitative information about mode mixing, splitting ratios, and reflection and transmission probabilities
Evidence of wave-particle duality for single fast hydrogen atoms.
Schmidt, H T; Fischer, D; Berenyi, Z; Cocke, C L; Gudmundsson, M; Haag, N; Johansson, H A B; Källberg, A; Levin, S B; Reinhed, P; Sassenberg, U; Schuch, R; Simonsson, A; Støchkel, K; Cederquist, H
2008-08-22
We report the direct observation of interference effects in a Young's double-slit experiment where the interfering waves are two spatially separated components of the de Broglie wave of single 1.3 MeV hydrogen atoms formed close to either target nucleus in H++H2 electron-transfer collisions. Quantum interference strongly influences the results even though the hydrogen atoms have a de Broglie wavelength, lambda_{dB}, as small as 25 fm. PMID:18764612
On Wave Dark Matter, Shells in Elliptical Galaxies, and the Axioms of General Relativity
Bray, Hubert L
2012-01-01
This paper is a sequel to the author's paper entitled "On Dark Matter, Spiral Galaxies, and the Axioms of General Relativity" [arXiv:1004.4016] which explored a geometrically natural axiomatic definition for dark matter modeled by a scalar field satisfying the Einstein-Klein-Gordon wave equations which, after much calculation, was shown to be consistent with the observed spiral and barred spiral patterns in disk galaxies. We give an update on where things stand on this "wave dark matter" model of dark matter (aka scalar field dark matter and boson stars), an interesting alternative to the WIMP model of dark matter, and discuss how it has the potential to help explain the long-observed interleaved shell patterns, also known as ripples, in the images of elliptical galaxies.
Intermixing between four-wave mixing and six-wave mixing in a four-level atomic system
Energy Technology Data Exchange (ETDEWEB)
Zhang Yanpeng; Brown, Andy W; Gan Chenli; Xiao Min [Department of Physics, University of Arkansas, Fayetteville, AR 72701 (United States)
2007-09-14
We investigate the interplay between six-wave mixing (SWM) and four-wave mixing (FWM) resulting from atomic coherence and polarization beat in a four-level atomic system. The dressed FWM evolution and competition pathways can be controlled by the coupling field to exhibit two FWM and SWM turning points, FWM+SWM, and FWM+FWM interference regions. Quantum interference between two FWM or one FWM and one SWM channels leads to nonlinear signal enhancement and suppression under different conditions. The fifth-order nonlinear response can be obtained by the phase control of the polarization beat between the FWM and SWM signals.
Massive gravitons as dark matter and gravitational waves
Aoki, Katsuki; Mukohyama, Shinji
2016-01-01
We consider the possibility that the massive graviton is a viable candidate of dark matter in the context of bimetric gravity. We first derive the energy-momentum tensor of the massive graviton and show that it indeed behaves as that of dark matter fluid. We then discuss a production mechanism and the present abundance of massive gravitons as dark matter. Since the metric to which ordinary matter fields couple is a linear combination of the two mass eigenstates of bigravity, production of mas...
Coherent manipulation of spin wave vector for polarization of photons in an atomic ensemble
Li, Shujing; Xu, Zhongxiao; Zheng, Haiyan; ZHAO, XINGBO; Wu, Yuelong; Wang, Hai; Xie, Changde; Peng, Kunchi
2011-01-01
We experimentally demonstrate the manipulation of two-orthogonal components of a spin wave in an atomic ensemble. Based on Raman two-photon transition and Larmor spin precession induced by magnetic field pulses, the coherent rotations between the two components of the spin wave is controllably achieved. Successively, the two manipulated spin-wave components are mapped into two orthogonal polarized optical emissions, respectively. By measuring Ramsey fringes of the retrieved optical signals, t...
Effects of ion-atom collisions on the propagation and damping of ion-acoustic waves
DEFF Research Database (Denmark)
Andersen, H.K.; D'Angelo, N.; Jensen, Vagn Orla;
1968-01-01
Experiments are described on ion-acoustic wave propagation and damping in alkali plasmas of various degrees of ionization. An increase of the ratio Te/Ti from 1 to approximately 3-4, caused by ion-atom collisions, results in a decrease of the (Landau) damping of the waves. At high gas pressure and....../or low wave frequency a "fluid" picture adequately describes the experimental results....
Baker, John G.; Thorpe, James Ira
2012-01-01
We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nea...
Cherif, Abour A.; Adams, Gerald E.; Cannon, Charles E.
1997-01-01
Describes several activities used to teach students from middle school age to college nonmajors about the nature of matter, atoms, molecules and the periodic table. Strategies integrate such approaches as hands-on activities, visualization, writing, demonstrations, role play, and guided inquiry. For example, the periodic table is viewed as a town…
International Nuclear Information System (INIS)
Full text: Full text: Frequency-modulation AFM can be combined with scanning tunneling microscopy, yielding a simultaneous data set for current and average force gradient. Ternes et al. have shown that for some metallic contacts, force and current are proportional. The figure shows an example, where combined AFM/STM reveals two strongly distinct aspects of the atomic structure of matter. The gray veil depicts the inverted tunneling current between a CO molecule adsorbed on Cu(111) and a tungsten tip, while the colored surface shows the corresponding force profiles, where the left image corresponds to a W tip oriented in a direction, the right to a direction and the bottom to a direction. While the simultaneous acquisition of current and force can reveal new information about the atomic and electronic structure of matter, the tunneling current can modify the atomic forces. This phantom force, a modification of the electrostatic attraction between tip and sample, originates in an alteration of the effective potential difference between tip and sample caused by strongly localized voltage drop induced by the tunneling current. The talk discusses the merits of combined STM/AFM as well as the challenges, in particular with respect to tip preparation and characterization. (author)
Coherent manipulation of spin-wave vector for polarization of photons in an atomic ensemble
Energy Technology Data Exchange (ETDEWEB)
Li Shujing; Xu Zhongxiao; Zheng Haiyan; Zhao Xingbo; Wu Yuelong; Wang Hai; Xie Changde; Peng Kunchi [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China)
2011-10-15
We experimentally demonstrate the manipulation of two orthogonal components of a spin wave in an atomic ensemble. Based on Raman two-photon transition and Larmor spin precession induced by magnetic field pulses, the coherent rotations between the two components of the spin wave are controllably achieved. Successively, the two manipulated spin-wave components are mapped into two orthogonal polarized optical emissions. By measuring Ramsey fringes of the retrieved optical signals, the {pi}/2-pulse fidelity of {approx}96% is obtained. The presented manipulation scheme can be used to build an arbitrary rotation for qubit operations in quantum information processing based on atomic ensembles.
Coherent manipulation of spin wave vector for polarization of photons in an atomic ensemble
Li, Shujing; Zheng, Haiyan; Zhao, Xingbo; Wu, Yuelong; Wang, Hai; Xie, Changde; Peng, Kunchi
2011-01-01
We experimentally demonstrate the manipulation of two-orthogonal components of a spin wave in an atomic ensemble. Based on Raman two-photon transition and Larmor spin precession induced by magnetic field pulses, the coherent rotations between the two components of the spin wave is controllably achieved. Successively, the two manipulated spin-wave components are mapped into two orthogonal polarized optical emissions, respectively. By measuring Ramsey fringes of the retrieved optical signals, the \\pi/2-pulse fidelity of ~96% is obtained. The presented manipulation scheme can be used to build an arbitrary rotation for qubit operations in quantum information processing based on atomic ensembles.
Coherent manipulation of spin-wave vector for polarization of photons in an atomic ensemble
International Nuclear Information System (INIS)
We experimentally demonstrate the manipulation of two orthogonal components of a spin wave in an atomic ensemble. Based on Raman two-photon transition and Larmor spin precession induced by magnetic field pulses, the coherent rotations between the two components of the spin wave are controllably achieved. Successively, the two manipulated spin-wave components are mapped into two orthogonal polarized optical emissions. By measuring Ramsey fringes of the retrieved optical signals, the π/2-pulse fidelity of ∼96% is obtained. The presented manipulation scheme can be used to build an arbitrary rotation for qubit operations in quantum information processing based on atomic ensembles.
A Gravitational Wave Detector Based on an Atom Interferometer Project
National Aeronautics and Space Administration — Gravitational waves are tiny perturbations in the curvature of space-time that arise from accelerating masses – according to Einstein’s general...
Flambaum, Victor
2016-05-01
Low-mass boson dark matter particles produced after Big Bang form classical field and/or topological defects. In contrast to traditional dark matter searches, effects produced by interaction of an ordinary matter with this field and defects may be first power in the underlying interaction strength rather than the second or fourth power (which appears in a traditional search for the dark matter). This may give a huge advantage since the dark matter interaction constant is extremely small. Interaction between the density of the dark matter particles and ordinary matter produces both `slow' cosmological evolution and oscillating variations of the fundamental constants including the fine structure constant alpha and particle masses. Recent atomic dysprosium spectroscopy measurements and the primordial helium abundance data allowed us to improve on existing constraints on the quadratic interactions of the scalar dark matter with the photon, electron and light quarks by up to 15 orders of magnitude. Limits on the linear and quadratic interactions of the dark matter with W and Z bosons have been obtained for the first time. In addition to traditional methods to search for the variation of the fundamental constants (atomic clocks, quasar spectra, Big Bang Nucleosynthesis, etc) we discuss variations in phase shifts produced in laser/maser interferometers (such as giant LIGO, Virgo, GEO600 and TAMA300, and the table-top silicon cavity and sapphire interferometers), changes in pulsar rotational frequencies (which may have been observed already in pulsar glitches), non-gravitational lensing of cosmic radiation and the time-delay of pulsar signals. Other effects of dark matter and dark energy include apparent violation of the fundamental symmetries: oscillating or transient atomic electric dipole moments, precession of electron and nuclear spins about the direction of Earth's motion through an axion condensate, and axion-mediated spin-gravity couplings, violation of Lorentz
Semi-classical description of matter wave interferometers and hybrid quantum systems
Energy Technology Data Exchange (ETDEWEB)
Schneider, Mathias
2015-02-16
This work considers the semi-classical description of two applications involving cold atoms. This is, on one hand, the behavior of a BOSE-EINSTEIN condensate in hybrid systems, i.e. in contact with a microscopic object (carbon nanotubes, fullerenes, etc.). On the other, the evolution of phase space distributions in matter wave interferometers utilizing ray tracing methods was discussed. For describing condensates in hybrid systems, one can map the GROSS-PITAEVSKII equation, a differential equation in the complex-valued macroscopic wave function, onto a system of two differential equations in density and phase. Neglecting quantum dispersion, one obtains a semiclassical description which is easily modified to incorporate interactions between condensate and microscopical object. In our model, these interactions comprise attractive forces (CASIMIR-POLDER forces) and loss of condensed atoms due to inelastic collisions at the surface of the object. Our model exhibited the excitation of sound waves that are triggered by the object's rapid immersion, and spread across the condensate thereafter. Moreover, local particle loss leads to a shrinking of the bulk condensate. We showed that the total number of condensed particles is decreasing potentially in the beginning (large condensate, strong mean field interaction), while it decays exponentially in the long-time limit (small condensate, mean field inetraction negligible). For representing the physics of matter wave interferometers in phase space, we utilized the WIGNER function. In semi-classical approximation, which again consists in ignoring the quantum dispersion, this representation is subject to the same equation of motion as classical phase space distributions, i.e. the LIOUVILLE equation. This implies that time evolution of theWIGNER function follows a phase space flow that consists of classical trajectories (classical transport). This means, for calculating a time-evolved distribution, one has know the initial
Semi-classical description of matter wave interferometers and hybrid quantum systems
International Nuclear Information System (INIS)
This work considers the semi-classical description of two applications involving cold atoms. This is, on one hand, the behavior of a BOSE-EINSTEIN condensate in hybrid systems, i.e. in contact with a microscopic object (carbon nanotubes, fullerenes, etc.). On the other, the evolution of phase space distributions in matter wave interferometers utilizing ray tracing methods was discussed. For describing condensates in hybrid systems, one can map the GROSS-PITAEVSKII equation, a differential equation in the complex-valued macroscopic wave function, onto a system of two differential equations in density and phase. Neglecting quantum dispersion, one obtains a semiclassical description which is easily modified to incorporate interactions between condensate and microscopical object. In our model, these interactions comprise attractive forces (CASIMIR-POLDER forces) and loss of condensed atoms due to inelastic collisions at the surface of the object. Our model exhibited the excitation of sound waves that are triggered by the object's rapid immersion, and spread across the condensate thereafter. Moreover, local particle loss leads to a shrinking of the bulk condensate. We showed that the total number of condensed particles is decreasing potentially in the beginning (large condensate, strong mean field interaction), while it decays exponentially in the long-time limit (small condensate, mean field inetraction negligible). For representing the physics of matter wave interferometers in phase space, we utilized the WIGNER function. In semi-classical approximation, which again consists in ignoring the quantum dispersion, this representation is subject to the same equation of motion as classical phase space distributions, i.e. the LIOUVILLE equation. This implies that time evolution of theWIGNER function follows a phase space flow that consists of classical trajectories (classical transport). This means, for calculating a time-evolved distribution, one has know the initial
Twin Matter Waves for Interferometry Beyond the Classical Limit
DEFF Research Database (Denmark)
Lücke, Bernd; Scherer, Manuel; Kruse, Jens;
2011-01-01
Interferometers with atomic ensembles constitute an integral part of modern precision metrology. However, these interferometers are fundamentally restricted by the shot noise limit, which can only be overcome by creating quantum entanglement among the atoms. We used spin dynamics in Bose-Einstein...
Dynamic effects of electromagnetic wave on a damped two-level atom
Zeng, Z Y; Kuang, L M; Zhang, L D
1999-01-01
We studied the dynamic effects of an electromagnetic(EM) wave with circular polarization on a two-level damped atom. The results demonstrate interesting ac Stark split of energy levels of damped atom. The split levels have different energies and lifetimes, both of which depend on the interaction and the damping rate of atom. When the frequency of the EM wave is tuned to satisfy the resonance condition in the strong coupling limit, the transition probability exhibits Rabi oscillation. Momentum transfer between atom and EM wave shows similar properties as the transition probability under resonance condition. For a damped atom interacting with EM field, there exists no longer stable state. More importantly, if the angular frequency of the EM wave is tuned the same as the atomic transition frequency and its amplitude is adjusted appropriately according to the damping coefficients, we can prepare a particular 'Dressed State' of the coupled system between atom and EM field and can keep the system coherently in this...
Stationary rotary force waves on the liquid-air core interface of a swirl atomizer
Chinn, J. J.; Cooper, D.; Yule, A. J.; Nasr, G. G.
2015-11-01
A one-dimensional wave equation, applicable to the waves on the surface of the air-core of a swirl atomizer is derived analytically, by analogy to the similar one-dimensional wave equation derivation for shallow-water gravity waves. In addition an analogy to the flow of water over a weir is used to produce an analytical derivation of the flow over the lip of the outlet of a swirl atomizer using the principle of maximum flow. The principle of maximum flow is substantiated by reference to continuity of the discharge in the direction of streaming. For shallow-water gravity waves, the phase velocity is the same expression as for the critical velocity over the weir. Similarly, in the present work, the wave phase velocity on the surface of the air-core is shown to be the same expression as for the critical velocity for the flow at the outlet. In addition, this wave phase velocity is shown to be the square root of the product of the radial acceleration and the liquid thickness, as analogous with the wave phase velocity for shallow water gravity waves, which is the square root of the product of the acceleration due to gravity and the water depth. The work revisits the weirs and flumes work of Binnie et al. but using a different methodology. The results corroborate with the work of Binnie. High speed video, Laser Doppler Anemometry and deflected laser beam experimental work has been carried out on an oversize Perspex (Plexiglas) swirl atomizer. Three distinctive types of waves were detected: helical striations, low amplitude random ripples and low frequency stationary waves. It is the latter wave type that is considered further in this article. The experimentally observed waves appear to be stationary upon the axially moving flow. The mathematical analysis allows for the possibility of a negative value for the phase velocity expression. Therefore the critical velocity and the wave phase velocity do indeed lead to stationary waves in the atomizer. A quantitative comparison
The Production of Strong Blast Waves through Intense Laser Irradiation of Atomic Clusters
International Nuclear Information System (INIS)
An understanding of radiation effects on the evolution of shock waves is of great importance to many problems in astrophysics. Shock waves driven by a laser-heated plasma are attractive for laboratory investigation of these phenomena. Recent studies of intense short-pulse laser interactions with gases of atomic clusters indicate a potential avenue to access this regime of radiative hydrodynamics. We have measured the energy absorption efficiency of high-intensity, picosecond laser pulses in low-density gases composed of large atomic clusters and find that the energy absorption can be very high (>95%), producing a high-temperature plasma filament which consequently produces a strong blast wave. Interferometric characterization of these shock waves indicates that in high-Z gases such as Xe, radiation transport plays an important role in the evolution of the shock wave. (c) 2000 The American Astronomical Society
Do Neutrino Wave Functions Overlap and Does it Matter?
Li, Cheng-Hsien
2016-01-01
Studies of neutrinos commonly ignore anti-symmetrization of their wave functions. This implicitly assumes that either spatial wave functions for neutrinos with approximately the same momentum do not overlap or their overlapping has no measurable consequences. We examine these assumptions by considering the evolution of three-dimensional neutrino wave packets (WPs). We find that it is perfectly adequate to treat accelerator and reactor neutrinos as separate WPs for typical experimental setup. While solar and supernova neutrinos correspond to overlapping WPs, they can be treated effectively as non-overlapping for analyses of their detection.
A discussion on the double wave theory and its applications to description of radiation atoms
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The double wave theory (DWT), sometimes called the“non_statistical quantum mechanics” by its proposer, describes the state of each single particle in an ensemble with two wave functions which have a parameter corresponding to the particle. However the basic postulates of the DWT show that this theory can hardly describe any quantum rules of the microscopic world. In the double wave descriptions, the wave feature of the behavior of microscopic particles and the discontinuity characteristic of energy almost disappear. The discussions on several problems of the radiation atoms made by the DWT's proposer on the basis of this theory are either mathematically incorrect or inconsistent with experiments and the usual theory.
Extracting chemical information from plane wave calculations by a 3D 'fuzzy atoms' analysis
Bakó, I.; Stirling, A.; Seitsonen, A. P.; Mayer, I.
2013-03-01
Bond order and valence indices have been calculated by the method of the three-dimensional 'fuzzy atoms' analysis, using the numerical molecular orbitals obtained from plane wave DFT calculations, i.e., without introducing any external atom-centered functions. Weight functions of both Hirshfeld and Becke types have been applied. The results are rather close to the similar 'fuzzy atoms' ones obtained by using atom-centered basis sets and agree well with the chemical expectations, stressing the power of the genuine chemical concepts.
Vacuum Rabi Oscillation of an Atom without Rotating-Wave Approximation
Institute of Scientific and Technical Information of China (English)
WANG Fa-Qiang; LIU Wei-Ci; LIANG Rui-Sheng
2008-01-01
@@ We have investigated vacuum Rabi oscillation of an atom coupled with single-mode cavity field exactly, and compared the results with that of the Jaynes-Cummings (J-C) model.The results show that for resonant case, there is no Rabi oscillation for an atom.For small detuning and weak coupling case, the probability for the atom in excited state oscillates against time with different frequencies and amplitudes from that of the J-C model.It exhibits that the counter-rotating wave interaction could significantly effect the dynamic hehaviour of the atom, even under the condition in which the RWA is considered to be justified.
Vacuum Rabi Oscillation of an Atom without Rotating-Wave Approximation
International Nuclear Information System (INIS)
We have investigated vacuum Rabi oscillation of an atom coupled with single-mode cavity field exactly, and compared the results with that of the Jaynes–Cummings (J–C) model. The results show that for resonant case, there is no Rabi oscillation for an atom. For small detuning and weak coupling case, the probability for the atom in excited state oscillates against time with different frequencies and amplitudes from that of the J-C model. It exhibits that the counter-rotating wave interaction could significantly effect the dynamic behaviour of the atom, even under the condition in which the RWA is considered to be justified
Time evolution of atomic inversion in a standing wave light field
Institute of Scientific and Technical Information of China (English)
Wen Yin(殷雯); Jiuqing Liang(梁九卿); Yunzhong Lai(赖云忠); Qiwei Yan(严启伟)
2003-01-01
The interaction between an atomic beam of two-level atoms and a standing wave light field has beenstudied by the exact solution of a time-dependent quantum system developed recently. When the initialatomic state is choosen to be ground, we find that with the limit of zero detuning the atoms will oscillatebetween the upper and the lower levels with a decaying amplitude. The most interesting result obtainedin this paper is when the initial atomic state is a particular superposition of the two levels, now the systemdoes not oscillate at any time.
Design and Fabrication of a Chip-based Continuous-wave Atom Laser
Power, E. P.; George, L; Vanderelzen, B.; Herrera-Fierro, P.; Murphy, R; Yalisove, S. M.; Raithel, G.
2012-01-01
We present a design for a continuous-wave (CW) atom laser on a chip and describe the process used to fabricate the device. Our design aims to integrate quadrupole magnetic guiding of ground state Rb atoms with continuous surface adsorption evaporative cooling to create a continuous Bose-Einstein condensate; out-coupled atoms from the condensate should realize a CW atom laser. We choose a geometry with three wires embedded in a spiral pattern in a silicon subtrate. The guide features an integr...
Manipulating localized matter waves in multicomponent Bose-Einstein condensates
Manikandan, K.; Muruganandam, P.; Senthilvelan, M.; Lakshmanan, M.
2016-03-01
We analyze vector localized solutions of two-component Bose-Einstein condensates (BECs) with variable nonlinearity parameters and external trap potentials through a similarity transformation technique which transforms the two coupled Gross-Pitaevskii equations into a pair of coupled nonlinear Schrödinger equations with constant coefficients under a specific integrability condition. In this analysis we consider three different types of external trap potentials: a time-independent trap, a time-dependent monotonic trap, and a time-dependent periodic trap. We point out the existence of different interesting localized structures; namely, rogue waves, dark- and bright-soliton rogue waves, and rogue-wave breatherlike structures for the above three cases of trap potentials. We show how the vector localized density profiles in a constant background get deformed when we tune the strength of the trap parameter. Furthermore, we investigate the nature of the trajectories of the nonautonomous rogue waves. We also construct the dark-dark rogue wave solution for the repulsive-repulsive interaction of two-component BECs and analyze the associated characteristics for the three different kinds of traps. We then deduce single-, two-, and three-composite rogue waves for three-component BECs and discuss the correlated characteristics when we tune the strength of the trap parameter for different trap potentials.
Energy Technology Data Exchange (ETDEWEB)
Mohamadou, Alidou [Condensed Matter Laboratory, Department of Physics, Faculty of Science, University of Douala, P.O. Box 24157, Douala (Cameroon); Abdus Salam International Centre for Theoretical Physics, P.O. Box 538, Strada Costiera 11, I-34014 Trieste (Italy); Wamba, Etienne; Kofane, Timoleon C. [Laboratory of Mechanics, Department of Physics, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde (Cameroon); Doka, Serge Y. [Higher Teacher Training College, University of Maroua, P.O. Box 55, Maroua (Cameroon); Ekogo, Thierry B. [Departement de Physique, Universite des Sciences et Techniques de Masuku, B.P. 943, Franceville (Gabonese Republic)
2011-08-15
We examine the generation of bright matter-wave solitons in the Gross-Pitaevskii equation describing Bose-Einstein condensates with a time-dependent complex potential, which is composed of a repulsive parabolic background potential and a gravitational field. By performing a modified lens-type transformation, an explicit expression for the growth rate of a purely growing modulational instability is presented and analyzed. We point out the effects of the gravitational field, as well as of the parameter related to the feeding or loss of atoms in the condensate, on the instability growth rate. It is evident from numerical simulations that the feeding with atoms and the magnetic trap have opposite effects on the dynamics of the system. It is shown that the feeding or loss parameter can be well used to control the instability domain. Our study shows that the gravitational field changes the condensate trail of the soliton trains during the propagation. We also perform a numerical analysis to solve the Gross-Pitaevskii equation with a time-dependent complicated potential. The numerical results on the effect of both the gravitational field and the parameter of feeding or loss of atoms in the condensate agree well with predictions of the linear stability analysis. Another result of the present work is the modification of the background wave function in the Thomas-Fermi approximation during the numerical simulations.
International Nuclear Information System (INIS)
We examine the generation of bright matter-wave solitons in the Gross-Pitaevskii equation describing Bose-Einstein condensates with a time-dependent complex potential, which is composed of a repulsive parabolic background potential and a gravitational field. By performing a modified lens-type transformation, an explicit expression for the growth rate of a purely growing modulational instability is presented and analyzed. We point out the effects of the gravitational field, as well as of the parameter related to the feeding or loss of atoms in the condensate, on the instability growth rate. It is evident from numerical simulations that the feeding with atoms and the magnetic trap have opposite effects on the dynamics of the system. It is shown that the feeding or loss parameter can be well used to control the instability domain. Our study shows that the gravitational field changes the condensate trail of the soliton trains during the propagation. We also perform a numerical analysis to solve the Gross-Pitaevskii equation with a time-dependent complicated potential. The numerical results on the effect of both the gravitational field and the parameter of feeding or loss of atoms in the condensate agree well with predictions of the linear stability analysis. Another result of the present work is the modification of the background wave function in the Thomas-Fermi approximation during the numerical simulations.
Driben, R.; Konotop, V. V.; Meier, T.
2016-03-01
Nonlinearity is the driving force for numerous important effects in nature typically showing transitions between different regimes, regular, chaotic or catastrophic behavior. Localized nonlinear modes have been the focus of intense research in areas such as fluid and gas dynamics, photonics, atomic and solid state physics etc. Due to the richness of the behavior of nonlinear systems and due to the severe numerical demands of accurate three-dimensional (3D) numerical simulations presently only little knowledge is available on the dynamics of complex nonlinear modes in 3D. Here, we investigate the dynamics of 3D non-coaxial matter wave vortices that are trapped in a parabolic potential and interact via a repulsive nonlinearity. Our numerical simulations demonstrate the existence of an unexpected and fascinating nonlinear regime that starts immediately when the nonlinearity is switched-on and is characterized by a smooth dynamics representing torque-free precession with nutations. The reported motion is proven to be robust regarding various effects such as the number of particles, dissipation and trap deformations and thus should be observable in suitably designed experiments. Since our theoretical approach, i.e., coupled nonlinear Schrödinger equations, is quite generic, we expect that the obtained novel dynamical behavior should also exist in other nonlinear systems.
Gravitational decoherence of atomic interferometers
Lamine, Brahim; Jaekel, Marc-Thierry; Reynaud, Serge
2002-01-01
We study the decoherence of atomic interferometers due to the scattering of stochastic gravitational waves. We evaluate the `direct' gravitational effect registered by the phase of the matter waves as well as the `indirect' effect registered by the light waves used as beam-splitters and mirrors for the matter waves. Considering as an example the space project HYPER, we show that both effects are negligible for the presently studied interferometers.
What is matter? The fundamental ontology of atomism and structural realism
Esfeld, Michael; Oldofredi, Andrea
2015-01-01
We set out a fundamental ontology of atomism in terms of matter points. While being most parsimonious, this ontology is able to match both classical and quantum mechanics, and it remains a viable option for any future theory of cosmology that goes beyond current quantum physics. The matter points are structurally individuated: all there is to them are the spatial relations in which they stand; neither a commitment to intrinsic properties nor to an absolute space is required. The spatial relations change. All that is needed to capture change is a dynamical structure, namely dynamical relations as expressed in terms of the dynamical parameters of a physical theory.
The pump-probe coupling of matter wave packets to remote lattice states
DEFF Research Database (Denmark)
Sherson, Jacob F; Park, Sung Jong; Pedersen, Poul Lindholm;
2012-01-01
The coherent manipulation of wave packets is an important tool in many areas of physics. We demonstrate the experimental realization of quasi-free wave packets of ultra-cold atoms bound by an external harmonic trap. The wave packets are produced by modulating the intensity of an optical lattice...... containing a Bose–Einstein condensate. The evolution of these wave packets is monitored in situ and their six-photon reflection at a band gap is observed. In direct analogy with pump–probe spectroscopy, a probe pulse allows for the resonant de-excitation of the wave packet into states localized around...... selected lattice sites at a long, controllable distance of more than 100 lattice sites from the main component. This precise control mechanism for ultra-cold atoms thus enables controlled quantum state preparation and splitting for quantum dynamics, metrology and simulation....
Experimental Evidence for the Attraction of Matter by Electromagnetic Waves
Lidgren, Hans
2010-01-01
We present measurement results demonstrating that a conducting lead sphere exposed to electromagnetic (e/m) waves in the infrared (IR) regime, is attracted by e/m waves. The result may seem surprising and against conventional wisdom that electromagnetic wave forcing should lead to a repulsive force. Nonetheless, all our experiments show that the attractive force can be determined quantitatively, and that they are reproducible. Our experiment setup is a Cavendish torsion-balance experiment with lead spheres, one of the spheres intermittently irradiated by IR light. Because the Cavendish experiment is well known, simple, and readily available, the results can be easily verified or falsified. However, to avoid Bernoulli and other external forcing effects, the entire experimental setup should be placed in a vacuum chamber. In our case the experiments were performed at \\approx 4 \\cdot 10^-7 mbar. One of the 20 g lead spheres was intermittently irradiated by infrared radiation from a lamp covered by an aluminium fo...
Towards Relativistic Atomic Physics and Post-Minkowskian Gravitational Waves
Luca LusannaINFN
2009-01-01
A review is given of the formulation of relativistic atomic theory, in which there is an explicit realization of the Poincare' generators, both in the inertial and in the non-inertial rest-frame instant form of dynamics in Minkowski space-time. This implies the need to solve the problem of the relativistic center of mass of an isolated system and to describe the transitions from different conventions for clock synchronization, namely for the identifications of instantaneous ...
Impurity-Mediated Early Condensation of a Charge Density Wave in an Atomic Wire Array.
Yeom, Han Woong; Oh, Deok Mahn; Wippermann, Stefan; Schmidt, Wolf Gero
2016-01-26
We directly show how impurity atoms induce the condensation of a representative electronic phase, the charge density wave (CDW) phase, in atomic scale with scanning tunneling microscopy. Oxygen impurity atoms on the self-assembled metallic atomic wire array on a silicon crystal condense the CDW locally above the pristine transition temperature. More interestingly, the CDW along the wires is induced not by a single atomic impurity but by the cooperation of multiple impurities. First-principles calculations disclose the mechanism of the cooperation as the coherent superposition of the local lattice strain induced by impurities, stressing the coupled electronic and lattice degrees of freedom for the CDW. This opens the possibility of the strain engineering over electronic phases of atomic-scale systems. PMID:26634634
Fully Quantized Theory of Six-Wave Mixing with Matter Waves
Institute of Scientific and Technical Information of China (English)
ZHU Wen-Xing; ZHOU Qing Ping; JIA Lei
2008-01-01
We show that Wu-Yang theory of fully quantized four-wave mixing can be generalized to the six-wave mixing and derive the analytical solution of the coupled equations describing the quantum dynamics of six-wave mixing.
Influence of separating distance between atomic sensors for gravitational wave detection
Tang, Biao; Zhou, Lin; Wang, Jin; Zhan, Mingsheng
2015-01-01
We consider a recent scheme of gravitational wave detection using atomic interferometers as inertial sensors, and reinvestigate its configuration using the concept of sensitivity functions. We show that such configuration can suppress noise without influencing the gravitational wave signal. But the suppression is insufficient for the direct observation of gravitational wave signals, so we analyse the behaviour of the different noises influencing the detection scheme. As a novel method, we study the relations between the measurement sensitivity and the distance between two interferometers, and find that the results derived from vibration noise and laser frequency noise are in stark contrast to that derived from the shot noise, which is significant for the configuration design of gravitational wave detectors using atomic interferometers.
Millimeter Wave Detection via Autler-Townes Splitting in Rubidium Rydberg Atoms
Gordon, Joshua A; Schwarzkopf, Andrew; Anderson, Dave A; Miller, Stephanie; Thaicharoen, Nithiwadee; Raithel, Georg
2014-01-01
In this paper we demonstrate the detection of millimeter waves via Autler-Townes splitting in 85Rb Rydberg atoms. This method may provide an independent, atom-based, SI-traceable method for measuring mm-wave electric fields, which addresses a gap in current calibration techniques in the mm-wave regime. The electric- field amplitude within a rubidium vapor cell in the WR-10 waveguide band is measured for frequencies of 93 GHz, and 104 GHz. Relevant aspects of Autler-Townes splitting originating from a four-level electromagnetically induced transparency scheme are discussed. We measure the E-field generated by an open-ended waveguide using this technique. Experimental results are compared to a full-wave finite element simulation.
Interplay of Coexisting Odd-Order Wave Mixings in a Five-Level Atomic System
Institute of Scientific and Technical Information of China (English)
SONG Yue; HUO Shu-Li; LI Pei-Ying; SANG Su-Ling; WANG Zhi-Guo; ZHANG Yan-Peng
2011-01-01
@@ We experimentally investigate the interplay between two coexisting six-wave mixing (SWM) signals and the interference between coexisting four-wave mixing (FWM) and SWM signals in a five-level atomic system of85 Rb.When two electromagnetically induced transparency windows gradually overlap in frequency, the competition between these two SWM signals arises.Moreover, we report the experimental result which shows that the temporal interference with femtosecond time scales between FWM and SWM signals.%We experimentally investigate the interplay between two coexisting six-wave mixing (SWM) signals and the interference between coexisting four-wave mixing (FWM) and SWM signals in a five-level atomic system of 85 Rb.When two electromagnetically induced transparency windows gradually overlap in frequency, the competition between these two SWM signals arises.Moreover, we report the experimental result which shows that the temporal interference with femtosecond time scales between FWM and SWM signals.
Carrier-wave Rabi flopping signatures in high-order harmonic generation for alkali atoms
Ciappina, M F; Landsman, A S; Zimmermann, T; Lewenstein, M; Roso, L; Krausz, F
2015-01-01
We present the first theoretical investigation of carrier-wave Rabi flopping in real atoms by employing numerical simulations of high-order harmonic generation (HHG) in alkali species. Given the short HHG cutoff, related to the low saturation intensity, we concentrate on the features of the third harmonic of sodium (Na) and potassium (K) atoms. For pulse areas of 2$\\pi$ and Na atoms, a characteristic unique peak appears, which, after analyzing the ground state population, we correlate with the conventional Rabi flopping. On the other hand, for larger pulse areas, carrier-wave Rabi flopping occurs, and is associated with a more complex structure in the third harmonic. These new characteristics observed in K atoms indicate the breakdown of the area theorem, as was already demonstrated under similar circumstances in narrow band gap semiconductors.
Roberts, B. M.; Dzuba, V. A.; Flambaum, V. V.; Pospelov, M.; Stadnik, Y. V.
2016-01-01
We revisit the WIMP-type dark matter scattering on electrons that results in atomic ionization, and can manifest itself in a variety of existing direct-detection experiments. Unlike the WIMP-nucleon scattering, where current experiments probe typical interaction strengths much smaller than the Fermi constant, the scattering on electrons requires a much stronger interaction to be detectable, which in turn requires new light force carriers. We account for such new forces explicitly, by introduc...
P-wave Annihilating Dark Matter from a Decaying Predecessor and the Galactic Center Excess
Choquette, Jeremie; Cline, James M.; Cornell, Jonathan M.
2016-01-01
Dark matter (DM) annihilations have been widely studied as a possible explanation of excess gamma rays from the galactic center seen by Fermi/LAT. However most such models are in conflict with constraints from dwarf spheroidals. Motivated by this tension, we show that p-wave annihilating dark matter can easily accommodate both sets of observations due to the lower DM velocity dispersion in dwarf galaxies. Explaining the DM relic abundance is then challenging. We outline a scenario in which th...
Dynamics and manipulation of matter-wave solitons in optical superlattices
Energy Technology Data Exchange (ETDEWEB)
Porter, Mason A. [Department of Physics and Center for the Physics of Information, California Institute of Technology, Pasadena, CA 91125 (United States); Kevrekidis, P.G. [Department of Mathematics and Statistics, University of Massachusetts, Amherst, MA 01003-4515 (United States)]. E-mail: kevrekid@math.umass.edu; Carretero-Gonzalez, R. [Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, San Diego State University, San Diego, CA 92182-7720 (United States); Frantzeskakis, D.J. [Department of Physics, University of Athens, Panepistimiopolis, Zografos, Athens 15784 (Greece)
2006-03-27
We study the existence and stability of bright, dark, and gap matter-wave solitons in optical superlattices. Then, using these properties, we show that (time-dependent) 'dynamical superlattices' can be used to controllably place, guide, and manipulate these solitons. In particular, we use numerical experiments to displace solitons by turning on a secondary lattice structure, transfer solitons from one location to another by shifting one superlattice substructure relative to the other, and implement solitonic 'path-following', in which a matter wave follows the time-dependent lattice substructure into oscillatory motion.
Compact dark matter objects, asteroseismology, and gravitational waves radiated by sun
International Nuclear Information System (INIS)
The solar surface oscillations observed by Crimean Astrophysical Observatory and Solar Helioseismic Observatory are considered to be excited by a small fraction of Dark Matter in form of Compact Dark Matter Objects (CDMO) in the solar structure. Gravitational Waves (GW) radiated by these CDMO are predicted to be the strongest at the Earth and are easily detectable by European Laser Interferometer Space Antenna or by Gravitational-Wave Observatory “Dulkyn” which can solve two the most challenging tasks in the modern physics: direct detection of GW and DM
Compact dark matter objects, asteroseismology, and gravitational waves radiated by sun
Energy Technology Data Exchange (ETDEWEB)
Pokrovsky, Yu. E., E-mail: Pokrovskiy-YE@nrcki.ru [National Research Center Kurchatov Institute (Russian Federation)
2015-12-15
The solar surface oscillations observed by Crimean Astrophysical Observatory and Solar Helioseismic Observatory are considered to be excited by a small fraction of Dark Matter in form of Compact Dark Matter Objects (CDMO) in the solar structure. Gravitational Waves (GW) radiated by these CDMO are predicted to be the strongest at the Earth and are easily detectable by European Laser Interferometer Space Antenna or by Gravitational-Wave Observatory “Dulkyn” which can solve two the most challenging tasks in the modern physics: direct detection of GW and DM.
Node-less atomic wave functions, Pauli repulsion and systematic projector augmentation
Blöchl, Peter E.; Först, Clemens
2012-01-01
A construction of node-less atomic orbitals and energy-dependent, node-reduced partial waves is presented, that contains the full information of the atomic eigenstates and that allows to represent the scattering properties in a transparent manner. By inverting the defining Schr\\"odinger equation, the Pauli repulsion by the core electrons can be represented as effective potential. This construction also provides a description of the Pauli repulsion by an environment. Furthermore, the represent...
Roberts, B M; Flambaum, V V; Pospelov, M; Stadnik, Y V
2016-01-01
We revisit the WIMP-type dark matter scattering on electrons that results in atomic ionization, and can manifest itself in a variety of existing direct-detection experiments. Unlike the WIMP-nucleon scattering, where current experiments probe typical interaction strengths much smaller than the Fermi constant, the scattering on electrons requires a much stronger interaction to be detectable, which in turn requires new light force carriers. We account for such new forces explicitly, by introducing a mediator particle with scalar or vector couplings to dark matter and to electrons. We then perform state of the art numerical calculations of atomic ionization relevant to the existing experiments. Our goals are to consistently take into account the atomic physics aspect of the problem (e.g., the relativistic effects, which can be quite significant), and to scan the parameter space: the dark matter mass, the mediator mass, and the effective coupling strength, to see if there is any part of the parameter space that c...
Close coupling wave packet theory of atom diatom scattering
International Nuclear Information System (INIS)
In the space-fixed (SF) coordinate frame and body-fixed (BF) coordinate frame, the state to state transitional probabilities for the He-H2 system are calculated by using the recently developed close coupling wave packet method. The results show that the two theories formulated in the SF frame and BF frame are equivalent, and the calculated results of the two method coincide with that of close coupling method, and that the calculational efficiency in the SF frame is higher than that in the BF frame as the number of coupled terms increases
Detecting dark matter waves with precision measurement tools
Derevianko, Andrei
2016-01-01
Virialized Ultra-Light Fields (VULFs) while being viable cold dark matter candidates can also solve the standard model hierarchy problem. Direct searches for VULFs due to their non-particle nature require low-energy precision measurement tools. Here we consider scalar VULF candidates. While the previous proposals have focused on detecting coherent oscillations of the measured signals at the VULF Compton frequencies at the device location, here we point out that VULFs also have a distinct spat...
Mode competition in superradiant scattering of matter waves
International Nuclear Information System (INIS)
Superradiant Rayleigh scattering in a Bose gas released from an optical lattice is analyzed with incident light pumping at the Bragg angle for resonant light diffraction. We show that competition between superradiance scattering into the Bragg mode and into end-fire modes clearly leads to suppression of the latter at even relatively low lattice depths. A quantum light-matter interaction model is proposed for qualitatively explaining this result.
Physics of Ultra-Cold Matter Atomic Clouds, Bose-Einstein Condensates and Rydberg Plasmas
Mendonça, J T
2013-01-01
The advent of laser cooling of atoms led to the discovery of ultra-cold matter, with temperatures below liquid Helium, which displays a variety of new physical phenomena. Physics of Ultra-Cold Matter gives an overview of this recent area of science, with a discussion of its main results and a description of its theoretical concepts and methods. Ultra-cold matter can be considered in three distinct phases: ultra-cold gas, Bose Einstein condensate, and Rydberg plasmas. This book gives an integrated view of this new area of science at the frontier between atomic physics, condensed matter, and plasma physics. It describes these three distinct phases while exploring the differences, as well as the sometimes unexpected similarities, of their respective theoretical methods. This book is an informative guide for researchers, and the benefits are a result from an integrated view of a very broad area of research, which is limited in previous books about this subject. The main unifying tool explored in this book is the ...
Strong light-matter coupling in two-dimensional atomic crystals
Liu, Xiaoze; Sun, Zheng; Xia, Fengnian; Lin, Erh-chen; Lee, Yi-Hsien; Kéna-Cohen, Stéphane; Menon, Vinod M
2014-01-01
Two dimensional (2D) atomic crystals of graphene, and transition metal dichalcogenides have emerged as a class of materials that show strong light-matter interaction. This interaction can be further controlled by embedding such materials into optical microcavities. When the interaction is engineered to be stronger than the dissipation of light and matter entities, one approaches the strong coupling regime resulting in the formation of half-light half-matter bosonic quasiparticles called microcavity polaritons. Here we report the evidence of strong light-matter coupling and formation of microcavity polaritons in a two dimensional atomic crystal of molybdenum disulphide (MoS2) embedded inside a dielectric microcavity at room temperature. A Rabi splitting of 46 meV and highly directional emission is observed from the MoS2 microcavity owing to the coupling between the 2D excitons and the cavity photons. Realizing strong coupling effects at room temperature in a disorder free potential landscape is central to the ...
Generating multi-atom entangled W states via light-matter interface based fusion mechanism.
Zang, Xue-Ping; Yang, Ming; Ozaydin, Fatih; Song, Wei; Cao, Zhuo-Liang
2015-01-01
W state is a key resource in quantum communication. Fusion technology has been proven to be a good candidate for preparing a large-size W state from two or more small-size W states in linear optical system. It is of great importance to study how to fuse W states via light-matter interface. Here we show that it is possible to prepare large-size W-state networks using a fusion mechanism in cavity QED system. The detuned interaction between three atoms and a vacuum cavity mode constitute the main fusion mechanism, based on which two or three small-size atomic W states can be fused into a larger-size W state. If no excitation is detected from those three atoms, the remaining atoms are still in the product of two or three new W states, which can be re-fused. The complicated Fredkin gate used in the previous fusion schemes is avoided here. W states of size 2 can be fused as well. The feasibility analysis shows that our fusion processes maybe implementable with the current technology. Our results demonstrate how the light-matter interaction based fusion mechanism can be realized, and may become the starting point for the fusion of multipartite entanglement in cavity QED system. PMID:26548649
Shock Wave Attenuation Using Foam Obstacles: Does Geometry Matter?
Directory of Open Access Journals (Sweden)
Hongjoo Jeon
2015-06-01
Full Text Available A shock wave impact study on open and closed cell foam obstacles was completed to assess attenuation effects with respect to different front face geometries of the foam obstacles. Five different types of geometries were investigated, while keeping the mass of the foam obstacle constant. The front face, i.e., the side where the incident shock wave impacts, were cut in geometries with one, two, three or four convergent shapes, and the results were compared to a foam block with a flat front face. Results were obtained by pressure sensors located upstream and downstream of the foam obstacle, in addition to high-speed schlieren photography. Results from the experiments show no significant difference between the five geometries, nor the two types of foam.
Gravity-related spontaneous wave function collapse in bulk matter
International Nuclear Information System (INIS)
In the DP-model, gravity-related spontaneous wave function collapses suppress Schrödinger cat states which are conceptually problematic especially for gravity and space-time. We derive the equations of the model for the hydrodynamic-elastic (acoustic) modes in a bulk. Two particular features are discussed: the universal dominance of spontaneous collapses at large wavelengths, and the reduction of spontaneous heating by a slight refinement of the DP-model. (paper)
Gravitational waves from dark matter collapse in a star
Kurita, Yasunari; Nakano, Hiroyuki
2016-01-01
We investigate the collapse of clusters of weakly interacting massive particles (WIMPs) in the core of a Sun-like star and the possible formation of mini-black holes and the emission of gravitational waves. When the number of WIMPs is small, thermal pressure balances the WIMP cluster's self gravity. If the number of WIMPs is larger than a critical number, thermal pressure cannot balance gravity and the cluster contracts. If WIMPs are collisionless and bosonic, the cluster collapses directly to form a mini-black hole. For fermionic WIMPs, the cluster contracts until it is sustained by Fermi pressure, forming a small compact object. If the fermionic WIMP mass is smaller than 4 ×102 GeV , the radius of the compact object is larger than its Schwarzschild radius and Fermi pressure temporally sustains its self-gravity, halting the formation of a black hole. If the fermionic WIMP mass is larger than 4 ×102 GeV , the radius is smaller than its Schwarzschild radius and the compact object becomes a mini-black hole. If the WIMP mass is 1 TeV, the size of the black hole will be approximately 2.5 cm and ultra high frequency gravitational waves will be emitted during black hole formation. The central frequency fc of ringdown gravitational waves emitted from the black hole will be approximately 2 GHz. To detect the ringdown gravitational waves, the detector's noise must be below √{Sh(fc) }≈1 0-30/√{Hz }.
Multiple photon-echo rephasing of coherent matter waves
Energy Technology Data Exchange (ETDEWEB)
Pan, Ruizhi; Yue, Xuguang; Xu, Xia; Lu, Haichang; Zhou, Xiaoji, E-mail: xjzhou@pku.edu.cn
2015-03-20
We investigate the multiple photon echo processes in a Bose–Einstein condensate (BEC) with inhomogeneous momentum broadening. By applying Bragg pulses with adjusted frequency mismatch to induce multiple rephasing, the BEC satisfies the coherence condition for successive superradiance. The atomic system can be efficiently transferred to a high momentum state step by step and emits multiple photon echo signals. These echo signals as a sequence show increasing widths and descending peaks, reflecting a residual dephasing effect due to kinetic-energy phase discrepancy during the population inversions. Our work may contribute to the coherence maintenance for ultracold atomic gas in the quantum information area and the high-precision measurement of atomic momentum width. - Highlights: • A multipulse protocol to induce multiple photon echo rephasing of a BEC is proposed. • Our method is a new and efficient way to transfer the BEC to high momentum modes. • Our method can extend a BEC's coherence time. • The echo sequence is analyzed to study the residual dephasing effect. • The echo decaying is useful in high-precision measurement of BEC's momentum width.
Multiple photon-echo rephasing of coherent matter waves
International Nuclear Information System (INIS)
We investigate the multiple photon echo processes in a Bose–Einstein condensate (BEC) with inhomogeneous momentum broadening. By applying Bragg pulses with adjusted frequency mismatch to induce multiple rephasing, the BEC satisfies the coherence condition for successive superradiance. The atomic system can be efficiently transferred to a high momentum state step by step and emits multiple photon echo signals. These echo signals as a sequence show increasing widths and descending peaks, reflecting a residual dephasing effect due to kinetic-energy phase discrepancy during the population inversions. Our work may contribute to the coherence maintenance for ultracold atomic gas in the quantum information area and the high-precision measurement of atomic momentum width. - Highlights: • A multipulse protocol to induce multiple photon echo rephasing of a BEC is proposed. • Our method is a new and efficient way to transfer the BEC to high momentum modes. • Our method can extend a BEC's coherence time. • The echo sequence is analyzed to study the residual dephasing effect. • The echo decaying is useful in high-precision measurement of BEC's momentum width
Evolution of spin-dependent atomic wave packets in a harmonic potential
Institute of Scientific and Technical Information of China (English)
Wen Ling-Hua; Liu Min; Kong Ling-Bo; Chen Ai-Xi; Zhan Ming-Sheng
2005-01-01
We have investigated theoretically the evolution of spin-dependent atomic wave packets in a harmonic magnetic trapping potential. For a Bose-condensed gas, which undergoes a Mott insulator transition and a spin-dependent transport, the atomic wavefunction can be described by an entangled single-atom state. Due to the confinement of the -harmonic potential, the density distributions exhibit periodic decay and revival, which is different from the case of free expansion after switching off the combined harmonic and optical lattice potential.
Comparison of LISA and Atom Interferometry for Gravitational Wave Astronomy in Space
Bender, Peter L
2011-01-01
One of the atom interferometer gravitational wave missions proposed by Dimopoulos et al.1 in 2008 was called AGIS-Sat. 2. It had a suggested gravitational wave sensitivity set by the atom state detection shot noise level that started at 1 mHz, was comparable to LISA sensitivity from 1 to about 20 mHz, and had better sensitivity from 20 to 500 mHz. The separation between the spacecraft was 1,000 km, with atom interferometers 200 m long and shades from sunlight used at each end. A careful analysis of many error sources was included, but requirements on the time-stability of both the laser wavefront aberrations and the atom temperatures in the atom clouds were not investigated. After including these considerations, the laser wavefront aberration stability requirement to meet the quoted sensitivity level is about 1\\times10-8 wavelengths, and is far tighter than for LISA. Also, the temperature fluctuations between atom clouds have to be less than 1 pK. An alternate atom interferometer GW mission in Earth orbit cal...
High-efficiency one-dimensional atom localization via two parallel standing-wave fields
International Nuclear Information System (INIS)
We present a new scheme of high-efficiency one-dimensional (1D) atom localization via measurement of upper state population or the probe absorption in a four-level N-type atomic system. By applying two classical standing-wave fields, the localization peak position and number, as well as the conditional position probability, can be easily controlled by the system parameters, and the sub-half-wavelength atom localization is also observed. More importantly, there is 100% detecting probability of the atom in the subwavelength domain when the corresponding conditions are satisfied. The proposed scheme may open up a promising way to achieve high-precision and high-efficiency 1D atom localization. (paper)
Observation of optical filtering effects with four-wave mixing in a cold atomic ensemble
Ding, Dong-Sheng; Zhang, Wei; Zhou, Zhi-Yuan; Shi, Bao-Sen; Guo, Guang-Can
2014-01-01
We observe an optical filtering effect in four-wave mixing (FWM) process based on a cold atomic gas. The side peaks appear at the edges of pulse of generated optical field, and they propagate through the atomic media without absorption. The theoretical analysis shows that these side peaks corresponded to the high frequency part of pulse of generated signal, which means the atoms cannot response to the rapid change of the electromagnetic field in time. On the contrary, the low frequency components of generated signal are absorbed during the transmission through the atoms. In addition, we experimentally demonstrate that the backward side peak could be stored by using Raman transition in atomic ensemble and retrieved later.
Baker, John G.; Thorpe, J. I.
2012-01-01
We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe. Whether this potential advantage outweighs the additional complexity associated with including atom interferometers will require further study.
Curceanu, Catalina; Bartalucci, Sergio; Bassi, Angelo; Bertolucci, Sergio; Berucci, Carolina; Bragadireanu, Alexandru Mario; Cargnelli, Michael; Clozza, Alberto; Di Matteo, Sergio; Donadi, S.; D'Uffizi, Alessandro; Egger, J.-P.; Guaraldo, Carlo; Iliescu, Mihail; Ishiwatari, Tomoichi; Laubenstein, Matthias; Marton, Johann; Milotti, Edoardo; Pietreanu, Dorel; Piscicchia, Kristian; Ponta, Titus; Sbardella, Emanuele; Scordo, Alessandro; Shi, Hexi; Sirghi, Diana; Sirghi, Florin; Sperandio, Laura; Doce, Oton Vazquez; Zmeskal, Johann
2014-12-01
The Pauli exclusion principle (PEP) and, more generally, the spin-statistics connection, are at the very basis of our understanding of matter, life and Universe. The PEP spurs, presently, a lively debate on its possible limits, deeply rooted in the very foundations of Quantum Mechanics. It is, therefore, extremely important to test the limits of its validity. The Violation of the PEP (VIP) experiment established the best limit on the probability that PEP is violated by electrons, using the method of searching for PEP forbidden atomic transitions in copper. We describe the experimental method, the obtained results, and plans to go beyond the actual limit by upgrading the experimental apparatus. We discuss the possibility of using a similar experimental technique to search for X-rays as a signature of the spontaneous collapse of the wave function predicted by continuous spontaneous localization (CSL) theories.
BEC and the New World of Coherent Matter Waves
Griffin, Allan
1999-01-01
This paper is based on three tutorial lectures given at the CRM Summer School in Banff, Alberta, June 27-July 10, 1999 on "Theoretical Physics at the End of the Twentieth Century". They will be published by Springer-Verlag. Lecture I gives a quick overview of recent studies of BEC in trapped atomic gases and reviews some properties of a trapped non-interacting Bose gas. Lecture II mainly discusses the collective modes of a pure condensate, based on the T=0 GP equation of motion. The Stringari...
P-wave holographic superconductor/insulator phase transitions affected by dark matter sector
Rogatko, Marek
2015-01-01
The holographic approach to building the p-wave superconductors results in three different models: the Maxwell-vector, the SU(2) Yang-Mills and the helical one. In the probe limit approximation, we analytically examine the properties of the first two models in the theory with {\\it dark matter} sector. It turns out that the effect of dark matter on the Maxwell-vector p-wave model is the same as on the s-wave superconductor studied earlier. For the non-Abelian model we study the phase transitions between p-wave holographic insulator/superconductor and metal/superconductor. Studies of marginally stable modes in the theory under consideration allow us to determine features of p-wave holographic droplet in a constant magnetic field. The superconducting transition temperature increases with the growth of the {\\it dark matter} sector coupling constant $\\alpha$, while the critical chemical potential $\\mu_c$ for the quantum phase transition between insulator and metal is a decreasing function of $\\alpha$.
A Resonant Mode for Gravitational Wave Detectors based on Atom Interferometry
Graham, Peter W; Kasevich, Mark A; Rajendran, Surjeet
2016-01-01
We describe a new atom interferometric gravitational wave detector design that can operate in a resonant mode for increased sensitivity. By oscillating the positions of the atomic wavepackets, this resonant detection mode allows for coherently enhanced, narrow-band sensitivity at target frequencies. The proposed detector is flexible and can be rapidly switched between broadband and narrow-band detection modes without changing hardware. For instance, a new binary discovered in broadband mode can subsequently be studied further as the inspiral evolves by using a tailored narrow-band detector response. In addition to functioning like a lock-in amplifier for astrophysical events, the enhanced sensitivity of the resonant approach also opens up the possibility of searching for important cosmological signals, including the stochastic gravitational wave background produced by inflation. We give an example of detector parameters which would allow detection of inflationary gravitational waves down to $\\Omega_\\text{GW} ...
International Nuclear Information System (INIS)
Optics and interferometry with matter waves is the art of coherently manipulating the translational motion of particles like neutrons, atoms and molecules. Coherent atom optics is an extension of techniques that were developed for manipulating internal quantum states. Applying these ideas to translational motion required the development of techniques to localize atoms and transfer population coherently between distant localities. In this view position and momentum are (continuous) quantum mechanical degrees of freedom analogous to discrete internal quantum states. In our contribution we start with an introduction into matter wave optics in sect. 1, discuss coherent atom optics and atom interferometry techniques for molecular beams in sect. 2 and for trapped atoms in sect. 3. In sect. 4 we then describe tools and experiments that allow to probe the evolution of quantum states of many-body systems by atom interference.
Self-modulation of a relativistic charged-particle beam as thermal matter wave envelope
International Nuclear Information System (INIS)
The self-modulation, resulting from its interaction with the surrounding medium, of a relativistic charged-particle beam traveling through an overdense plasma, is investigated theoretically. The description of the transverse nonlinear and collective beam dynamics of an electron (or positron) beam in a plasma-based accelerator is provided in terms of a thermal matter wave envelope propagation. This is done using the quantum-like description provided by the thermal wave model. It is shown that the charged-particle beam dynamics is governed by a Zakharov-type system of equations, comprising a nonlinear Schrödinger equation that is governing the spatiotemporal evolution of the thermal matter wave envelope and a Poisson-like equation for the wake potential that is generated by the bunch itself
Room temperature strong light-matter coupling in 3D THz meta-atoms (Conference Presentation)
Paulillo, Bruno; Manceau, Jean-Michel; Li, Lianhe; Linfield, Edmund; Colombelli, Raffaele
2016-04-01
We demonstrate strong light-matter coupling at room temperature in the terahertz (THz) spectral region using 3D meta-atoms with extremely sub-wavelength volumes. Using an air-bridge fabrication scheme, we have implemented sub-wavelength 3D THz micro-resonators that rely on suspended loop antennas connected to semiconductor-filled patch cavities. We have experimentally shown that they possess the functionalities of lumped LC resonators: their frequency response can be adjusted by independently tuning the inductance associated the antenna element or the capacitance provided by the metal-semiconductor-metal cavity. Moreover, the radiation coupling and efficiency can be engineered acting on the design of the loop antenna, similarly to conventional RF antennas. Here we take advantage of this rich playground in the context of cavity electrodynamics/intersubband polaritonics. In the strong light-matter coupling regime, a cavity and a two-level system exchange energy coherently at a characteristic rate called the vacuum Rabi frequency ΩR which is dominant with respect to all other loss mechanisms involved. The signature, in the frequency domain, is the appearance of a splitting between the bare cavity and material system resonances: the new states are called upper and a lower polariton branches. So far, most experimental demonstrations of strong light-matter interaction between an intersubband transition and a deeply sub-wavelength mode in the THz or mid-infrared ranges rely on wavelength-scale or larger resonators such as photonic crystals, diffractive gratings, dielectric micro-cavities or patch cavities. Lately, planar metamaterials have been used to enhance the light-matter interaction and strongly reduce the interaction volume by engineering the electric and magnetic resonances of the individual subwavelength constituents. In this contribution we provide evidence of strong coupling between a THz intersubband transition and an extremely sub-wavelength mode (≈λ/10
Matter wave solitons in coupled system with external potentials
International Nuclear Information System (INIS)
We present Lax-pair corresponding to the coupled Gross-Pitaevskii equation (CGPE) which governs the evolution of the macroscopic wave function of two components Bose-Einstein condensates trapped in time-dependent harmonic potential. Kinds of soliton solutions can be derived from the Lax-pair through Darboux transformation conveniently. Furthermore, soliton management in two-component Bose-Einstein condensate would be realized base on that the shape and motion of soliton in both components are investigated analytically. Moreover, it is found that there is a transformation existed between the nonautonomous coupled system and Manakov model. -- Highlights: → We derive the Lax-pair of coupled GP equation with external potentials. → The corresponding Darboux transformation is presented. → The bright-bright solitons are presented as an example. → Soliton manipulation could be realized theoretically in our model. → A transformation is presented to transform the CGP to Manakov system.
Matter and light wave interferometry in gravitational fields
International Nuclear Information System (INIS)
The phenomenon of quantum mechanical interference fringes for particles (neutron) travelling along different paths through the earth's gravitational field is discussed. An attempt is made to answer the question of describing such effects when the gravitational field is not simply Newtonian; and the full tensor character of gravitation comes into play. In the assumption of the 'semi-classical limit' the quantity of interest is the quantum mechanical phase accumulated by the travelling particle along its classical path. The idea of gauge variance is suggested by analogy with the equivalent problem in electrodynamics. Novel effects appear, such as gravity waves incident onto an interferometer; another interesting class of non-Newtonian situations has to do with rotational effects
Design and Fabrication of a Chip-based Continuous-wave Atom Laser
Power, E P; Vanderelzen, B; Herrera-Fierro, P; Murphy, R; Yalisove, S M; Raithel, G
2012-01-01
We present a design for a continuous-wave (CW) atom laser on a chip and describe the process used to fabricate the device. Our design aims to integrate quadrupole magnetic guiding of ground state Rb atoms with continuous surface adsorption evaporative cooling to create a continuous Bose-Einstein condensate; out-coupled atoms from the condensate should realize a CW atom laser. We choose a geometry with three wires embedded in a spiral pattern in a silicon subtrate. The guide features an integrated solenoid to mitigate spin-flip losses and provide a tailored longitudinal magnetic field. Our design also includes multiple options for atom interferometry: accomodations are in place for laser-generated atom Fabry-Perot and Mach-Zehnder interferometers, and a pair of atomic beam X-splitters is incorporated for an all-magnetic atom Mach-Zehnder setup. We demonstrate the techniques necessary to fabricate our device using existing micro- and nano-scale fabrication equipment, and discuss future options for modified desi...
Strong light-matter coupling from atoms to solid-state systems
2014-01-01
The physics of strong light-matter coupling has been addressed in different scientific communities over the last three decades. Since the early eighties, atoms coupled to optical and microwave cavities have led to pioneering demonstrations of cavity quantum electrodynamics, Gedanken experiments, and building blocks for quantum information processing, for which the Nobel Prize in Physics was awarded in 2012. In the framework of semiconducting devices, strong coupling has allowed investigations into the physics of Bose gases in solid-state environments, and the latter holds promise for exploiting light-matter interaction at the single-photon level in scalable architectures. More recently, impressive developments in the so-called superconducting circuit QED have opened another fundamental playground to revisit cavity quantum electrodynamics for practical and fundamental purposes. This book aims at developing the necessary interface between these communities, by providing future researchers with a robust conceptu...
Introduction to the physics of matter basic atomic, molecular, and solid-state physics
Manini, Nicola
2014-01-01
This book offers an up-to-date, compact presentation of basic topics in the physics of matter, from atoms to molecules to solids, including elements of statistical mechanics. The adiabatic separation of the motion of electrons and nuclei in matter and its spectroscopic implications are outlined for molecules and recalled regularly in the study of the dynamics of gases and solids. Numerous experiments are described and more than 160 figures give a clear visual impression of the main concepts. Sufficient detail of mathematical derivations is provided to enable students to follow easily. The focus is on present-day understanding and especially on phenomena fitting various independent-particle models. The historical development of this understanding, and phenomena such as magnetism and superconductivity, where interparticle interactions and nonadiabatic effects play a crucial role, are mostly omitted. A final outlook section stimulates the curiosity of the reader to pursue the study of such advanced topics in gra...
The stability of matter from atoms to stars : selecta of Elliott H. Lieb
Lieb, Elliott H
2005-01-01
This collection of papers -- starting with a brilliant article by one of the masters of the field -- gives an excellent current review of our knowledge of matter. Partially basing his own work on a variational formulation of quantum mechanics, E.H. Lieb links the difficult question of the stability of matter with important problems in functional analysis. Here the reader will find general results together with deep insights into quantum systems combined with papers on the structure of atoms and molecules, the thermodynamic limit, and stellar structures. The book is suitable as an accompanying text or recommended reading for a graduate course in quantum mechanics. In the third edition, two new sections were added: one contains papers on quantum electrodynamics, and the other on Boson systems. In this fourth edition, these topics have been further developed, extending the book by approximately 120 pages.
Buendía, E.; Gálvez, F. J.; Maldonado, P.; Sarsa, A.
2014-11-01
Total energies calculated from explicitly correlated wave functions for the ground state of the atoms Li to Sr and their singly charged anions and cations are obtained. Accurate all electron, non-relativistic Variational and Diffusion Monte Carlo energies are reported. The quality of the results, when comparing with exact estimations and experimental electron affinities and ionization potential is similar for all of the atoms studied. The parameterization of the explicitly correlated wave functions for all of the atomic systems studied is provided.
Gravitational waves from dark matter collapse in a star
Kurita, Yasunari
2016-01-01
We investigate the collapse of clusters of weakly interacting massive particles (WIMPs) in the core of a Sun-like star and the possible formation of mini-black holes and the emission of gravity waves. When the number of WIMPs is small, thermal pressure balances the WIMP cluster's self gravity. If the number of WIMPs is larger than a critical number, thermal pressure cannot balance gravity and the cluster contracts. If WIMPs are collisionless and bosonic, the cluster collapses directly to form a mini-black hole. For fermionic WIMPs, the cluster contracts until it is sustained by Fermi pressure, forming a small compact object. If the fermionic WIMP mass is smaller than $4\\times 10^2$ GeV, the radius of the compact object is larger than its Schwarzschild radius and Fermi pressure temporally sustains its self gravity, halting the formation of a black hole. If the fermionic WIMP mass is larger than $4\\times 10^2$ GeV, the radius is smaller than its Schwarzschild radius and the compact object becomes a mini-black h...
New prospects and techniques for matter wave interferometry with ions
Schütz, Georg; Pooch, Andreas; Schneeweiss, Philipp; Rauschenbeutel, Arno; Hwang, Ing-Shouh; Stibor, Alexander
2013-01-01
We present new developments and potential applications for the first ion-interferometer realized by Maier et al. [1-4], that verified at the end of the last century biprism interference and diffraction of 3 keV helium ions. The design of the setup is based on a coherent field emission source, an electrostatically charged biprism wire as a beam splitter and a multi-channel plate detector. However, due to deficiencies of the coherent ion source in the setup of Maier et al., the interference signal was low, therefore long integration times had to be accepted. In addition, the production of a significant uncharged particle radiation produced a high background intensity. The rest of the instrument proved to have excellent electron and ion optical properties and a high mechanical and electrical stability. Here we describe in detail the original setup and the major innovations to overcome the deficiencies. We introduce a novel single-atom metal tip [5] as a stable, coherent and monochromatic field emission ion sourc...
Stability of matter-wave solitons in optical lattices
Ali, Sk. Golam; Roy, S. K.; Talukdar, B.
2010-08-01
We consider localized states of both single- and two-component Bose-Einstein condensates (BECs) confined in a potential resulting from the superposition of linear and nonlinear optical lattices and make use of Vakhitov-Kolokolov criterion to investigate the effect of nonlinear lattice on the stability of the soliton solutions in the linear optical lattice (LOL). For the single-component case we show that a weak nonlinear lattice has very little effect on the stability of such solitons while sufficiently strong nonlinear optical lattice (NOL) squeezes them to produce narrow bound states. For two-component condensates we find that when the strength of the NOL (γ1) is less than that of the LOL (V0) a relatively weak intra-atomic interaction (IAI) has little effect on the stability of the component solitons. This is true for both attractive and repulsive IAI. A strong attractive IAI, however, squeezes the BEC solitons while a similar repulsive IAI makes the component solitons wider. For γ1 > V0, only a strong attractive IAI squeezes the BEC solitons but the squeezing effect is less prominent than that found for γ1 < V0. We make useful checks on the results of our semianalytical stability analysis by solving the appropriate Gross-Pitaevskii equations numerically.
Baker, John G.
2012-01-01
We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.
Generating multi-atom entangled W states via light-matter interface based fusion mechanism
Xue-Ping Zang; Ming Yang; Fatih Ozaydin; Wei Song; Zhuo-Liang Cao
2016-01-01
W state is a key resource in quantum communication. Fusion technology has been proven to be a good candidate for preparing a large-size W state from two or more small-size W states in linear optical system. It is of great importance to study how to fuse W states via light-matter interface. Here we show that it is possible to prepare large-size W-state networks using a fusion mechanism in cavity QED system. The detuned interaction between three atoms and a vacuum cavity mode constitute the mai...
Focus on topological physics: from condensed matter to cold atoms and optics
Zhai, Hui; Rechtsman, Mikael; Lu, Yuan-Ming; Yang, Kun
2016-08-01
The notions of a topological phase and topological order were first introduced in the studies of integer and fractional quantum Hall effects, and further developed in the study of topological insulators and topological superconductors in the past decade. Topological concepts are now widely used in many branches of physics, not only limited to condensed matter systems but also in ultracold atomic systems, photonic materials and trapped ions. Papers published in this focus issue are direct testaments of that, and readers will gain a global view of how topology impacts different branches of contemporary physics. We hope that these pages will inspire new ideas through communication between different fields.
Improved limits on interactions of low-mass spin-0 dark matter from atomic clock spectroscopy
Stadnik, Y. V.; Flambaum, V. V.
2016-08-01
Low-mass (sub-eV) spin-0 dark matter particles, which form a coherently oscillating classical field ϕ =ϕ0cos(mϕt ) , can induce oscillating variations in the fundamental constants through their interactions with the standard model sector. We calculate the effects of such possible interactions, which may include the linear interaction of ϕ with the Higgs boson, on atomic and molecular transitions. Using recent atomic clock spectroscopy measurements, we derive limits on the linear interaction of ϕ with the Higgs boson, as well as its quadratic interactions with the photon and light quarks. For the linear interaction of ϕ with the Higgs boson, our derived limits improve on existing constraints by up to 2-3 orders of magnitude.
Improved limits on interactions of low-mass spin-0 dark matter from atomic clock spectroscopy
Stadnik, Y V
2016-01-01
Low-mass (sub-eV) spin-0 dark matter particles, which form a coherently oscillating classical field $\\phi = \\phi_0 \\cos(m_\\phi t)$, can induce oscillating variations in the fundamental constants through their interactions with the Standard Model sector. We calculate the effects of such possible interactions, which may include the linear interaction of $\\phi$ with the Higgs boson, on atomic and molecular transitions. Using recent atomic clock spectroscopy measurements, we derive new limits on the linear interaction of $\\phi$ with the Higgs boson, as well as its quadratic interactions with the photon and light quarks. For the linear interaction of $\\phi$ with the Higgs boson, our derived limits improve on existing constraints by up to $2-3$ orders of magnitude.
International Nuclear Information System (INIS)
The exact solution to the problem of reflection and diffraction of atomic de Broglie waves by a travelling evanescent wave is found starting with a bare-state formulation. The solution for the wavefunctions, the tunnelling losses and the non-adiabatic losses are given exactly in terms of hyper-Bessel functions, and are valid for all detuning and Rabi frequencies, thus generalizing previous approximate methods. Furthermore we give the limiting cases of all amplitudes in the uniform semiclassical limit, which is valid in all regions including near the classical turning points, and in the large and weak coupling cases. Exact results for the zero detuning case are obtained in terms of Bessel functions. We find our uniform semiclassical limit to be closer to the exact result over the full range of parameter values than the previously reported calculations. The current knowledge of hyper-Bessel function properties is reviewed in order to apply this to the physical problems imposed
The Einstein-Klein-Gordon Equations, Wave Dark Matter, and the Tully-Fisher Relation
Goetz, Andrew S
2015-01-01
We examine the Einstein equation coupled to the Klein-Gordon equation for a complex-valued scalar field. These two equations together are known as the Einstein-Klein-Gordon system. In the low-field, non-relativistic limit, the Einstein-Klein-Gordon system reduces to the Poisson-Schr\\"odinger system. We describe the simplest solutions of these systems in spherical symmetry, the spherically symmetric static states, and some scaling properties they obey. We also describe some approximate analytic solutions for these states. The EKG system underlies a theory of wave dark matter, also known as scalar field dark matter (SFDM), boson star dark matter, and Bose-Einstein condensate (BEC) dark matter. We discuss a possible connection between the theory of wave dark matter and the baryonic Tully-Fisher relation, which is a scaling relation observed to hold for disk galaxies in the universe across many decades in mass. We show how fixing boundary conditions at the edge of the spherically symmetric static states implies T...
Three-Photon Resonant Nondegenerate Six-Wave Mixing in a Dressed Atomic System
Institute of Scientific and Technical Information of China (English)
SUN Jiang; FU Guang-Sheng; SU Hong-Xin; ZUO Zhan-Chun; WU Ling-An; FU Pan-Ming
2008-01-01
We report a three-photon resonant nondegenerate six-wave mixing (NSWM) in a dressed cascade five-level system.It has advantages that phase match condition is not stringent and NSWM signal is enhanced tremendously due to the multiple resonance with the atomic transition frequencies. In the presence of a strong coupling field,the threephoton resonant NSWM spectrum exhibits Autler-Townes splitting. This technique provides a spectroscopic tool for measuring not only the resonant frequency and dephasing rate but also the transition dipole moment between two highly excited atomic states.
Gravitational Wave Signatures of Dark Matter Sub-Millimeter Primordial Black Holes
Davoudiasl, Hooman
2016-01-01
We entertain the possibility that primordial black holes of mass $\\sim (10^{24} - 10^{26})$ g, with sub-millimeter Schwarzschild radii, constitute all or a significant fraction of cosmic dark matter, as allowed by various constraints. In case such primordial black holes get captured in orbits around neutron stars or astrophysical black holes in our galactic neighborhood, gravitational waves from the resulting "David & Goliath" binaries could be detectable at Advanced LIGO or Advanced Virgo from days to years, for a range of possible parameters. The proposed Einstein Telescope would further expand the reach for dark matter primordial black holes in this search mode.
Directory of Open Access Journals (Sweden)
E. A. K. Ford
2008-02-01
Full Text Available Data from the Fabry-Perot Interferometers at KEOPS (Sweden, Sodankylä (Finland, and Svalbard (Norway, have been analysed for gravity wave activity on all the clear nights from 2000 to 2006. A total of 249 nights were available from KEOPS, 133 from Sodankylä and 185 from the Svalbard FPI. A Lomb-Scargle analysis was performed on each of these nights to identify the periods of any wave activity during the night. Comparisons between many nights of data allow the general characteristics of the waves that are present in the high latitude upper thermosphere to be determined. Comparisons were made between the different parameters: the atomic oxygen intensities, the thermospheric winds and temperatures, and for each parameter the distribution of frequencies of the waves was determined. No dependence on the number of waves on geomagnetic activity levels, or position in the solar cycle, was found. All the FPIs have had different detectors at various times, producing different time resolutions of the data, so comparisons between the different years, and between data from different sites, showed how the time resolution determines which waves are observed. In addition to the cutoff due to the Nyquist frequency, poor resolution observations significantly reduce the number of short-period waves (<1 h period that may be detected with confidence. The length of the dataset, which is usually determined by the length of the night, was the main factor influencing the number of long period waves (>5 h detected. Comparisons between the number of gravity waves detected at KEOPS and Sodankylä over all the seasons showed a similar proportion of waves to the number of nights used for both sites, as expected since the two sites are at similar latitudes and therefore locations with respect to the auroral oval, confirming this as a likely source region. Svalbard showed fewer waves with short periods than KEOPS data for a season when both had the same time resolution data
Baker, John; Thorpe, Ira
2012-01-01
Thoroughly studied classic space-based gravitational-wave missions concepts such as the Laser Interferometer Space Antenna (LISA) are based on laser-interferometry techniques. Ongoing developments in atom-interferometry techniques have spurred recently proposed alternative mission concepts. These different approaches can be understood on a common footing. We present an comparative analysis of how each type of instrument responds to some of the noise sources which may limiting gravitational-wave mission concepts. Sensitivity to laser frequency instability is essentially the same for either approach. Spacecraft acceleration reference stability sensitivities are different, allowing smaller spacecraft separations in the atom interferometry approach, but acceleration noise requirements are nonetheless similar. Each approach has distinct additional measurement noise issues.
Sarsa, A.; Buendía, E.; Gálvez, F. J.
2016-07-01
Explicitly correlated wave functions to study confined atoms under impenetrable spherical walls have been obtained. Configuration mixing and a correlation factor are included in the variational ansatz. The behaviors of the ground state and some low-lying excited states of He, Be, B and C atoms with the confinement size are analyzed. Level crossing with confinement is found for some cases. This effect is analyzed in terms of the single particle energy of the occupied orbitals. The multi-configuration parameterized optimized effective potential method is employed with a cut-off factor to account for Dirichlet boundary conditions. The variational Monte Carlo method is used to deal with explicitly correlated wave functions.
Kadlecová, Hedvika; Weber, Stefan; Korn, Georg
2016-01-01
We analyze theoretical models of gravitational waves generation in the interaction of high intensity laser with matter, namely ablation and piston models. We analyse the generated gravitational waves in linear approximation of gravitational theory. We derive the analytical formulas and estimates for the metric perturbations and the radiated power of generated gravitational waves. Furthermore we investigate the characteristics of polarization and the behaviour of test particles in the presence of gravitational wave which will be important for the detection.
Energy Technology Data Exchange (ETDEWEB)
Lee, Hyun Kyu
2014-01-15
Recent developments of gravitational wave detectors like LIGO and Virgo provide us an optimistic opportunity of expecting first few events in near future. One of the exciting possibilities is that we can probe the inner structure of compact objects like neutron star by analyzing the observed pattern of gravitational waves. Among the characteristic features of the equation of state (EoS), the symmetry energy of dense hadronic matter is discussed. A model which implements a new scaling law of physical parameters of hadronic matter is briefly sketched to demonstrate how it affects the equation of state and the outcome for the mass and radius estimation is discussed for an n-p asymmetric configuration.
Analysis of the loss of coherence in interferometry with matter waves
International Nuclear Information System (INIS)
Full text: We succinctly analyze the various processes inducing loss of coherence in the interference produced by macromolecules diffracted by a grating. The results obtained by numerical simulations show a good agreement with experimental data (e.g., recent experiments with fullerene). This analysis fits also with other interferometry experiments performed by means of matter waves. For instance, as a byproduct, we investigate possible interferometry experiments to test randomness in the arrival times of light particles (e.g., neutrons). (author)
Gravitational waves in Fully Constrained Formulation in a dynamical spacetime with matter content
Energy Technology Data Exchange (ETDEWEB)
Cordero-Carrion, Isabel; Cerda-Duran, Pablo [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85741, Garching (Germany); Ibanez, Jose MarIa, E-mail: chabela@mpa-garching.mpg.de, E-mail: cerda@mpa-garching.mpg.de, E-mail: jose.m.ibanez@uv.es [Departamento de AstronomIa y Astrofisica, Universidad de Valencia, C/ Dr. Moliner 50, E-46100 Burjassot, Valencia (Spain)
2011-09-22
We analyze numerically the behaviour of the hyperbolic sector of the Fully Constrained Formulation (FCF) (Bonazzola et al. 2004). The numerical experiments allow us to be confident in the performances of the upgraded version of the CoCoNuT code (Dimmelmeier et al. 2005) by replacing the Conformally Flat Condition (CFC), an approximation of Einstein equations, by FCF. First gravitational waves in FCF in a dynamical spacetime with matter content will be shown.
Position-momentum correlations in matter waves double-slit experiment
Neto, J. S. M.; da Paz, I. G.; Cabral, L. A.
2014-01-01
We present a treatment of the double-slit interference of matter-waves represented by Gaussian wavepackets. The interference pattern is modelled with Green's function propagator which emphasizes the coordinate correlations and phases. We explore the connection between phases and position-momentum correlations in the intensity, visibility and predictability of the wavepackets interference. This formulation will indicate some aspects that can be useful for theoretical and experimental treatment...
Variational analysis of a matter-wave soliton scattering by external potentials
International Nuclear Information System (INIS)
Full text: Dynamics of the width and center-of-mass position of a matter-wave soliton interacting with arbitrary external potential is analyzed using the collective coordinates approach. It is shown that approximation of the trial function and external potential only in the interaction region of the spatial domain is sufficient for adequate description of the soliton scattering process. The validity of the developed approach is illustrated for the Gaussian and Poschl-Teller potentials. (author)
Fortov, Vladimir E.
2007-04-01
The physical properties of hot dense matter over a broad domain of the phase diagram are of immediate interest in astrophysics, planetary physics, power engineering, controlled thermonuclear fusion, impulse technologies, enginery, and several special applications. The use of intense shock waves in dynamic physics and high-pressure chemistry has made the exotic high-energy-density states of matter a subject of laboratory experiments and enabled advancing by many orders of magnitude along the pressure scale to range into the megabars and even gigabars. The present report reviews the latest experimental research involving shock waves in nonideal plasmas under conditions of strong collective interparticle interaction. The results of investigations into the thermodynamic, transport, and optical properties of strongly compressed hot matter, as well as into its composition and conductivity, are discussed. Experimental techniques for high energy density cumulation, the drivers of intense shock waves, and methods for the fast diagnostics of high-energy plasma are considered. Also discussed are compression-stimulated physical effects: pressure-induced ionization, plasma phase transitions, the deformation of bound states, plasma blooming ('transparentization' of plasma), etc. Suggestions for future research are put forward.
Constraining dark matter late-time energy injection: decays and p-wave annihilations
International Nuclear Information System (INIS)
We use the latest cosmic microwave background (CMB) observations to provide updated constraints on the dark matter lifetime as well as on p-wave suppressed annihilation cross sections in the 1 MeV to 1 TeV mass range. In contrast to scenarios with an s-wave dominated annihilation cross section, which mainly affect the CMB close to the last scattering surface, signatures associated with these scenarios essentially appear at low redshifts (z∼<50) when structure began to form, and thus manifest at lower multipoles in the CMB power spectrum. We use data from Planck, WMAP9, SPT and ACT, as well as Lyman–α measurements of the matter temperature at z ∼ 4 to set a 95% confidence level lower bound on the dark matter lifetime of ∼ 4 × 1025 s for mχ = 100 MeV. This bound becomes lower by an order of magnitude at mχ = 1 TeV due to inefficient energy deposition into the intergalactic medium. We also show that structure formation can enhance the effect of p-wave suppressed annihilation cross sections by many orders of magnitude with respect to the background cosmological rate, although even with this enhancement, CMB constraints are not yet strong enough to reach the thermal relic value of the cross section
Size Effects on Surface Elastic Waves in a Semi-Infinite Medium with Atomic Defect Generation
Directory of Open Access Journals (Sweden)
F. Mirzade
2013-01-01
Full Text Available The paper investigates small-scale effects on the Rayleigh-type surface wave propagation in an isotopic elastic half-space upon laser irradiation. Based on Eringen’s theory of nonlocal continuum mechanics, the basic equations of wave motion and laser-induced atomic defect dynamics are derived. Dispersion equation that governs the Rayleigh surface waves in the considered medium is derived and analyzed. Explicit expressions for phase velocity and attenuation (amplification coefficients which characterize surface waves are obtained. It is shown that if the generation rate is above the critical value, due to concentration-elastic instability, nanometer sized ordered concentration-strain structures on the surface or volume of solids arise. The spatial scale of these structures is proportional to the characteristic length of defect-atom interaction and increases with the increase of the temperature of the medium. The critical value of the pump parameter is directly proportional to recombination rate and inversely proportional to deformational potentials of defects.
Narrowband switchable dual-passband atomic filter with four-wave mixing optical amplification
Institute of Scientific and Technical Information of China (English)
Zheng Tan; Xianping Sun; Jun Luo; Yong Cheng; Jin Wang; Mingsheng Zhan
2011-01-01
@@ By using Faraday optical filter combined with four-wave mixing (FWM) amplifier, a narrow bandwidth optical amplifying atomic filter with switchable dual-passband is demonstrated experimentally. The two transmission peaks of the filter correspond to the Stokes and anti-Stokes frequencies, exhibiting a Raman gain in 13- and 17-fold, respectively, with bandwidth of ～120 MHz. By properly setting pump laser detuning, switching between filter passbands is realized. We also investigate the dependence of peak transmission on both pump laser intensity and Rb cell temperature. This atomic filter can find practical applications in long-distance laser communications and laser remote-sensing systems.%By using Faraday optical filter combined with four-wave mixing (FWM) amplifier, a narrow bandwidth optical amplifying atomic filter with switchable dual-passband is demonstrated experimentally. The two transmission peaks of the filter correspond to the Stokes and anti-Stokes frequencies, exhibiting a Raman gain in 13- and 17-fold, respectively, with bandwidth of ～120 MHz. By properly setting pump laser detuning, switching between filter passbands is realized. We also investigate the dependence of peak transmission on both pump laser intensity and Rb cell temperature. This atomic filter can find practical applications in long-distance laser communications and laser remote-sensing systems.
Nonlinear polariton waves in an optical double lattice with photo-induced transport of atoms
International Nuclear Information System (INIS)
The process of photo-induced transport of cold atoms in optical lattices is discussed for the case in which the direct tunneling of atoms is suppressed but transport of an atom is possible as a result of simultaneous absorption and reemission of two photons with different energies. Proceeding from the Bose-Hubbard model for two kinds of traps of a one-dimensional optical lattice, a set of equations describing the propagation of an ultrashort pulse of biharmonic radiation accompanied by a transfer of populations of traps of such a double lattice is derived. It was found that, depending on the choice of boundary conditions, there exist two types of stationary solitary waves corresponding to the propagation of a coupled pair of soliton pulses: a pair of bright solitons and a coupled pair of dark and bright solitons
Hydrogen atom wave function and eigen energy in the Rindler space
Dai, De-Chang
2016-01-01
We study the hydrogen atom eigenstate energy and wave function in the Rindler space. The probability distribution is tilted because the electric field of the nucleus is no longer spherically symmetric. The hydrogen atom therefore cannot be treated exactly in the same way as what it is in an inertial frame. We also find that if the external force accelerates only the nucleus and then the nucleus accelerates its surrounding electrons through electromagnetic force, the electrons can tunnel through the local energy gap and split the hydrogen atom into an ion. This is similar to what one expects from the Stark effect. However, the critical acceleration is about $3\\times 10^{22} m/s^2$. It is well beyond the gravitational acceleration on a regular star surface.
Non-linear interactions of multi-level atoms with a near-resonant standing wave
International Nuclear Information System (INIS)
Using a semiclassical density matrix formalism we have calculated the behavior of multi-level atoms interacting with a standing wave field, and show how complex non-linear phenomena, including multi-photon effects, combine to produce saturation spectra as observed in experiments. We consider both 20-level sodium and 24-level rubidium models, contrasting these with a simple 2-level case. The influence of parameters such as atomic trajectory and the time the atom remains in the beam are shown to have a critical effect on the lineshape of these resonances and the emission/absorption processes. Stable oscillations in the excited state populations for both the two-level and multi-level cases are shown to be limit cycles. These limit cycles undergo period doubling as the system evolves into chaos. Finally, using a Monte Carlo treatment, these processes average to produce saturated absorption spectra complete with power and Doppler broadening effects consistent with experiment. (authors)
P-wave Annihilating Dark Matter from a Decaying Predecessor and the Galactic Center Excess
Choquette, Jeremie; Cornell, Jonathan M
2016-01-01
Dark matter (DM) annihilations have been widely studied as a possible explanation of excess gamma rays from the galactic center seen by Fermi/LAT. However most such models are in conflict with constraints from dwarf spheroidals. Motivated by this tension, we show that p-wave annihilating dark matter can easily accommodate both sets of observations due to the lower DM velocity dispersion in dwarf galaxies. Explaining the DM relic abundance is then challenging. We outline a scenario in which the usual thermal abundance is obtained through s-wave annihilations of a metastable particle, that eventually decays into the p-wave annihilating DM of the present epoch. The couplings and lifetime of the decaying particle are constrained by big bang nucleosynthesis, the cosmic microwave background and direct detection, but significant regions of parameter space are viable. A sufficiently large p-wave cross section can be found by annihilation into light mediators, that also give rise to Sommerfeld enhancement. A predictio...
p -wave annihilating dark matter from a decaying predecessor and the Galactic Center excess
Choquette, Jeremie; Cline, James M.; Cornell, Jonathan M.
2016-07-01
Dark matter (DM) annihilations have been widely studied as a possible explanation of excess gamma rays from the Galactic Center seen by Fermi/LAT. However most such models are in conflict with constraints from dwarf spheroidals. Motivated by this tension, we show that p -wave annihilating dark matter can easily accommodate both sets of observations due to the lower DM velocity dispersion in dwarf galaxies. Explaining the DM relic abundance is then challenging. We outline a scenario in which the usual thermal abundance is obtained through s -wave annihilations of a metastable particle, that eventually decays into the p -wave annihilating DM of the present epoch. The couplings and lifetime of the decaying particle are constrained by big bang nucleosynthesis, the cosmic microwave background and direct detection, but significant regions of parameter space are viable. A sufficiently large p -wave cross section can be found by annihilation into light mediators, that also give rise to Sommerfeld enhancement. A prediction of the scenario is enhanced annihilations in galaxy clusters.
Fourth American Physical Society Topical Conference on Shock Waves in Condensed Matter
Shock Waves in Condensed Matter
1986-01-01
The Fourth American Physical Society Topical Conference on Shock Waves in Condensed Matter was held in Spokane, Washington, July 22-25, 1985. Two hundred and fifty scientists and engineers representing thirteen countries registered at the conference. The countries represented included the United States of America, Australia, Canada, The People's Repub lic of China, France, India, Israel, Japan, Republic of China (Taiwan), United Kingdom, U. S. S. R, Switzerland and West Germany. One hundred and sixty-two technical papers, cov ering recent developments in shock wave and high pressure physics, were presented. All of the abstracts have been published in the September 1985 issue of the Bulletin of the American Physical Society. The topical conferences, held every two years since 1979, have become the principal forum for shock wave studies in condensed materials. Both formal and informal technical discussions regarding recent developments conveyed a sense of excitement. Consistent with the past conferences, th...
Montemayor-Aldrete, J A; Morones-Ibarra, J R; Morales-Mori, A; Cabrera-Bravo, E; Montemayor-Varela, A
2005-01-01
It is shown that the entropy of low density monochromatic gravitational waves, waves required for the stabilization of the crystalline structure of vacuum cosmic space, varies with the volume in the same manner as the entropy of an ideal gas formed by particles. This implies that close enough to the big-bang event the energy of all the 10 to the 120 power gravitational waves, under an adiabatic compression process, which stabilizes the crystalline structure of vacuum space behaves thermodynamically as though it is consisted of a number nB = 10 to the 80 power of independent energy or matter quanta (neutrons). PACS numbers: 03.50.De, 03.65.-w, 04.20.-q, 61.50.-f, 65.50.+m, 98.80.Ft, 97.60.Lf
Yang–Baxter integrable models in experiments: from condensed matter to ultracold atoms
International Nuclear Information System (INIS)
The Yang–Baxter equation has long been recognised as the masterkey to integrability, providing the basis for exactly solved models which capture the fundamental physics of a number of realistic classical and quantum systems. In this article we provide an introductory survey of the impact of Yang–Baxter integrable models on experiments in condensed matter physics and ultracold atoms. A number of prominent examples are covered, including the hard-hexagon model, the Heisenberg spin chain, the transverse quantum Ising chain, a spin ladder model, the Lieb–Liniger Bose gas, the Gaudin–Yang Fermi gas and the two-site Bose–Hubbard model. The review concludes by pointing to some other recent developments with promise for further progress. (review)
Aspects of the theory of atoms and coherent matter and their interaction with electromagnetic fields
Energy Technology Data Exchange (ETDEWEB)
Nilsen, Halvor Moell
2002-07-01
In the present work I have outlined and contributed to the time-dependent theory of the interaction between atoms and electromagnetic fields and the theory of Bose-Einstein condensates. New numerical methods and algorithms have been developed and applied in practice. Calculations have exhibited certain new dynamical features. All these calculations are in a regime where the applied field is of the same magnitude as the atomic field. In the case of BEC we have investigated the use of time-dependent methods to calculate the excitation frequencies. We also investigated the possibility of nonlinear coupling for a scissors mode and found no such contributions to damping which is consistent with other studies . Special emphasis has also been paid to the gyroscopic motion of rotating BEC where several models were investigated. Briefly, the main conclusions are: (1) Rydberg wave packets appear for direct excitations of Rydberg atoms for long pulses. (2) The survival of just a few states is decided by symmetry of the Hamiltonian. (3) For few cycle intense pulses classical and quantum mechanics show remarkable similarity. (4) Time-dependent methods for finding excitation frequencies have been shown to be very efficient. (5) New dynamical features is shown in gyroscopic motion of BEC. (6) It was shown that no nonlinear mixing of scissors modes occur in the standard Gross-Pitaevskii regime. As mentioned in the introduction, this work is a part of very active research fields and new progress is constantly reported. Thus, the present work cannot be concluded as a closed loop. The fast development of grid based numerical solutions for atoms in intense fields will surely make great contribution to solve many of today's problems. It is a very important area of research to understand both nonperturbative atomic response and highly nonlinear optics. In the field of Bose-Einstein condensation the new experimental achievements constantly drive the field forward. The new
The structure of warm dense matter modeled with an average atom model with ion-ion correlations
Saumon, D.; Starrett, C. E.; Anta, J. A.; Daughton, W.; Chabrier, G.
2013-01-01
We present a new model of warm dense matter that represents an intermediate approach between the relative simplicity of ''one-ion'' average atom models and the more realistic but computationally expensive ab initio simulation methods. Physical realism is achieved primarily by including the correlations in the plasma that surrounds a central ion. The plasma is described with the Ornstein-Zernike integral equations theory of fluids, which is coupled to an average atom model for the central ion....
Wave-packet continuum-discretization approach to ion-atom collisions: Nonrearrangement scattering
Abdurakhmanov, I. B.; Kadyrov, A. S.; Bray, I.
2016-08-01
A general single-center close-coupling approach based on a continuum-discretization procedure is developed to calculate excitation and ionization processes in ion-atom collisions. The continuous spectrum of the target is discretized using stationary wave packets constructed from the Coulomb wave functions, the eigenstates of the target Hamiltonian. Such continuum discretization allows one to generate pseudostates with arbitrary energies and distribution. These features are ideal for detailed differential ionization studies. The approach starts from the semiclassical three-body Schrödinger equation for the scattering wave function and leads to a set of coupled differential equations for the transition probability amplitudes. To demonstrate its utility the method is applied to calculate collisions of antiprotons with atomic hydrogen. A comprehensive set of benchmark results from integrated to fully differential cross sections for antiproton-impact ionization of hydrogen in the energy range from 1 keV to 1 MeV is provided. Contrary to previous predictions, we find that at low incident energies the singly differential cross section has a maximum away from the zero emission energy. This feature could not be seen without a fine discretization of the low-energy part of the continuum.
Scaled plane-wave Born cross sections for atoms and molecules
Tanaka, H.; Brunger, M. J.; Campbell, L.; Kato, H.; Hoshino, M.; Rau, A. R. P.
2016-04-01
Integral cross sections for optically allowed electronic-state excitations of atoms and molecules by electron impact, by applying scaled plane-wave Born models, are reviewed. Over 40 years ago, Inokuti presented an influential review of charged-particle scattering, based on the theory pioneered by Bethe forty years earlier, which emphasized the importance of reliable cross-section data from low eV energies to high keV energies that are needed in many areas of radiation science with applications to astronomy, plasmas, and medicine. Yet, with a couple of possible exceptions, most computational methods in electron-atom scattering do not, in general, overlap each other's validity range in the region from threshold up to 300 eV and, in particular, in the intermediate region from 30 to 300 eV. This is even more so for electron-molecule scattering. In fact this entire energy range is of great importance and, to bridge the gap between the two regions of low and high energy, scaled plane-wave Born models were developed to provide reliable, comprehensive, and absolute integral cross sections, first for ionization by Kim and Rudd and then extended to optically allowed electronic-state excitation by Kim. These and other scaling models in a broad, general application to electron scattering from atoms and molecules, their theoretical basis, and their results for cross sections along with comparison to experimental measurements are reviewed. Where possible, these data are also compared to results from other computational approaches.
Schive, Hsi-Yu; Chiueh, Tzihong; Broadhurst, Tom; Huang, Kuan-Wei
2015-01-01
The newly established luminosity functions of high-z galaxies at $4 \\lesssim z \\lesssim 10$ can provide a stringent check on dark matter models that aim to explain the core properties of dwarf galaxies. The cores of dwarf spheroidal galaxies are understood to be too large to be accounted for by free streaming of warm dark matter without overly suppressing the formation of such galaxies. Here we demonstrate with cosmological simulations that wave dark matter, $\\psi$DM, appropriate for light bo...
Spatial interference of coherent atomic waves by manipulation of the internal quantum state.
Fort, C; Maddaloni, P; Minardi, F; Modugno, M; Inguscio, M
2001-07-15
A trapped >(87)Rb Bose-Einstein condensate is initially put into a superposition of two internal states. Under the effect of gravity and by means of a second transition, we prepare two vertically displaced condensates in the same internal state. These constitute two coherent sources of matter waves with adjustable spatial separation. Fringe patterns, observed after free expansion, are associated with the interplay between internal and external degrees of freedom and substantially agree with those for a double-slit experiment. PMID:18049512
Laser desorption/vaporization/ionization techniques for matter-wave interferometry
International Nuclear Information System (INIS)
Full text: Testing the delocalization of individual massive objects is an exciting experimental challenge of modern quantum physics and substantial progress in matter-wave interferometry with complex particles has led to the establishment of quantum-assisted molecule metrology and advanced investigations at the boundary between the classical and quantum mechanical evolution of very massive objects. New interferometers have led to demonstrations of the quantum wave nature of organic molecules beyond 10 000 amu and even of clusters of molecules. One of the major challenges for future interference experiments with large particles is the production of a neutral and slow molecular beam. We aim at particles with a mass beyond 104 u that should travel with sufficient intensity, low internal temperature and low transverse velocity. Here we present a series of experiments characterizing different laser desorption sources for future quantum interference experiments, the Quantum LIMES (Laser Induced Molecule Evaporation Sources). We describe the matrix-free laser desorption and laser-induced acoustic desorption (LIAD) with subsequent UV/VUV photoionization in combination with time-of-flight mass spectrometry. We present mass spectra and velocity distributions of large tailor-made perfluoroalkyl-functionalized molecules as well as more thermo labile biomolecules and we discuss the suitability of LIAD for matter wave interferometry. (author)
Das, J N; Paul, S
2003-01-01
Hyperspherical partial wave theory has been applied here in the study of photo double ionization of the helium atom for equal energy sharing geometry at 20 eV excess energy. Calculations have been done both in length and velocity gauges and are found to agree nicely with each other, with the CCC results and with experiments and exhibit some advantages of the corresponding three particle wave function over other wave functions in use.
Atomic origin of the scanning tunneling microscopy images of charge-density-waves on 1T-TaSe2
International Nuclear Information System (INIS)
We show atomically resolved scanning tunneling microscopy (STM) images of charge density waves (CDWs) at room temperature together with angle-resolved photoelectron band-mapping of 1T-TaSe2. By comparing the results of these two techniques, we demonstrate the atomic structure of the CDW-features observed by the STM and atomic origin of the reconstructed band-structure in this material
Pion cloud contribution to the s-wave repulsion in pionic atoms
International Nuclear Information System (INIS)
The nuclear pion cloud contribution to the pion self-energy for pionic atoms is evaluated and one finds large cancellations between terms involving the ππ amplitude and other terms originating from the chiral lagrangian partners. While the individual terms depend strongly on the off-shell extrapolation of the ππ amplitude, the sum is model independent within the Olson and Turner family of chiral lagrangians keeping ξ+4η constant, as previously found for the πN →ππN and pion double-charge exchange in nuclei, and vanishes in the limit of mπ→0. One finds a small net repulsion which is however too small to account for the ''missing'' s-wave repulsion. A revision of the present status of the problem of the ''missing'' s-wave repulsion is done at the end. ((orig.))
Observation of four-wave mixing in caesium atoms using a noncycling transition
Institute of Scientific and Technical Information of China (English)
Wang Li-Rong; Ma Jie; Zhao Jian-Ming; Xiao Lian-Tuan; Jia Suo-Tang
2006-01-01
In this paper the generation of four-wave mixing (FWM) signal using a noncycling transition of caesium atoms is investigated when the pumping laser is locked to the transition 6S1/2F = 4 → 6P3/2F' = 4, and meanwhile the probe frequency is scanned across the 6S1/2F = 4 → 6P3/2 transition. The efficiency of the four-wave mixing signal as a function of the intensity of the pumping beams and the detuning of the pumping beams is also studied. In order to increase the detection efficiency, a repumping laser which is resonant with 6S1/2F = 3 → 6P3/2F' = 4 transition is used. A theoretical model is also introduced, and the theoretical results are in qualitative agreement with experimental ones.
Friend, James R; Yeo, Leslie Y; Arifin, Dian R; Mechler, Adam
2008-04-01
We demonstrate a straightforward and rapid atomization process driven by surface acoustic waves that is capable of continuously producing spherical monodispersed submicron poly-ε-caprolactone particle aggregates between 150 and 200 nm, each of which are composed of nanoparticles of 5-10 nm in diameter. The size and morphologies of these particle assemblies were determined using dynamic light scattering, atomic force microscopy and transmission electron microscopy. Through scaling theory, we show that the larger particle aggregates are formed due to capillary instabilities amplified by the acoustic forcing whereas the smaller particulates that form the aggregates arise due to a nucleate templating process as a result of rapid spatially inhomogeneous solvent evaporation. Minimization of the free energy associated with the evaporative process yields a critical cluster size for a single nucleus in the order of 10 nm, which roughly corresponds with the dimensions of the sub-50 nm particulates. PMID:21817755
Influence of laser power on deposition of the chromium atomic beam in laser standing wave
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
One-dimensional deposition of collimated Cr atomic beam focused by a near-resonant Gaussian standing-laser field with wavelength of 425.55 nm is examined from particle-optics approach by using an adaptive step size,fourth-order Runge-Kutta type algorithm.The influence of laser power on deposition of atoms in laser standing wave is discussed and the simulative result shows that the FWHM of nanometer stripe is 102 nm and contrast is 2:1 with laser power equal to 3 mW,the FWHM is 1.2 nm and contrast is 32:1 with laser power equal to 16 mW,but with laser power increase,equal to 50 mW,the nonmeter structure forms the multi-crests and exacerbates.
Institute of Scientific and Technical Information of China (English)
ZHANG Wen-Tao; ZHU Bao-Hua
2009-01-01
One-dimensional deposition of a neutral chromium atomic beam focused by a near-resonant Gaussian standing-laser field is discussed by using a fourth-order Runge-Kutta type algorithm. The deposition pattern of neutral chromium atoms in a laser standing wave with different laser power is discussed and the simulation result shows that the full width at half maximum (FWHM) of a nanometer stripe is 115nm and the contrast is 2.5:1 with laser power 3.93mW; the FWHM is 0.Snm and the contrast is 27:1 with laser power 16mW, the optimal laser power; but with laser power increasing to 50mW, the nanometer structure forms multi-crests and the quality worsens quickly with increasing laser power.
Determination of dopant atomic positions with kinematical X-ray standing waves
International Nuclear Information System (INIS)
Recent advances in the kinematic X-ray standing wave technique (KXSW) for the determination of the atomic coordinates and displacement parameters in nonperfect crystalline materials are described in this thesis. The methodology has been improved by considering three significant aspects: - the inclusion of weak multiple beam contributions - the excitation of secondary fluorescence in multiple-element samples - the influence of the crystal mosaicity on the fluorescence yield. The improvements allowed to successfully apply the method to investigate complex oxide materials of current interest for potential device applications. The thermally-induced interdiffusion of cobalt and manganese thin films on zinc oxide single crystals has been studied to determine which lattice sites are occupied preferentially. The data analysis revealed that after thermal diffusion the adsorbed atoms occupied zinc sites in the host lattice. The mean deviation of the cobalt atomic position from the zinc lattice site was comparable to the thermal displacement parameter of the zinc atoms. In the case of manganese a secondary phase was found on the surface. Measurements performed on LaSrMnO4 provided new insight concerning the rotation of the oxygen octahedron around the manganese atoms and the concomitant displacements of the strontium and lanthanum atoms. It was found that the oxygen octahedra are rotated around the [100]-direction by 4,5 . The measurements in transmission geometry performed on titanium dioxide (rutile) demonstrated that KXSW measurements in the Laue geometry is a viable technique. By performing KXSW under grazing-incidence conditions it is possible to achieve depth resolution. The results clearly show that the extended KXSW technique is a versatile method for characterizing complex material systems. (orig.)
Atom-field entanglement in the Jaynes-Cummings model without rotating wave approximation
Mirzaee, M.; Batavani, M.
2015-04-01
In this paper, we present a structure for obtaining the exact eigenfunctions and eigenvalues of the Jaynes-Cummings model (JCM) without the rotating wave approximation (RWA). We study the evolution of the system in the strong coupling region using the time evolution operator without RWA. The entanglement of the system without RWA is investigated using the Von Neumann entropy as an entanglement measure. It is interesting that in the weak coupling regime, the population of the atomic levels and Von Neumann entropy without RWA model shows a good agreement with the RWA whereas in strong coupling domain, the results of these two models are quite different.
Resolution for Forward and Phase-Conjugate Degenerate Four-Wave Mixing in Hot Atomic Media
International Nuclear Information System (INIS)
Resolutions of degenerate four-wave mixing with forward and phase-conjugate configurations (FDFWM and PCDFWM) are investigated and compared theoretically and experimentally in hot rubidium (Rb) atomic vapor. The theoretical simulations indicate that PCDFWM is of much higher resolution than FDFWM. The resolution of PCDFWM is less dependent on Doppler broadening. The experimental results are in good agreement with the theoretical expectation. PCDFWM can resolve the hyperfine transitions and crossover resonances of 87Rb which cannot be achieved by FDFWM. Additionally, with sample temperature increasing, the linewidth of FDFWM spectrum obviously broadens. In comparison, no obvious broadening can be observed in the PCDFWM spectrum. (fundamental areas of phenomenology(including applications))
Continuous-wave, single-frequency 229 nm laser source for laser cooling of cadmium atoms
Kaneda, Yushi; Yarborough, J. M.; Merzlyak, Yevgeny; Yamaguchi, Atsushi; Hayashida, Keitaro; Ohmae, Noriaki; Katori, Hidetoshi
2016-01-01
Continuous-wave output at 229 nm for the application of laser cooling of Cd atoms was generated by the 4th harmonic using two successive second harmonic generation stages. Employing a single-frequency optically pumped semiconductor laser as a fundamental source, 0.56 W of output at 229 nm was observed with a 10-mm long, Brewster-cut BBO crystal in an external cavity with 1.62 W of 458 nm input. Conversion efficiency from 458 nm to 229 nm was more than 34%. By applying a tapered amplifier as a...
A ``local observables'' method for wave mechanics applied to atomic hydrogen
Bowman, Peter J.
2008-12-01
An alternative method of deriving the values of the observables of atomic systems is presented. Rather than using operators and eigenvalues the local variables method uses the continuity equation together with current densities derived from wave functions that are solutions of the Dirac or Pauli equation. The method is applied to atomic hydrogen using the usual language of quantum mechanics rather than that of geometric algebra with which the method is often associated. The picture of the atom that emerges is one in which the electron density as a whole is rotating about a central axis. The results challenge some assumptions of conventional quantum mechanics. Electron spin is shown to be a property of the dynamical motion of the electron and not an intrinsic property of the electron, the ground state of hydrogen is shown to have an orbital angular momentum of ℏ, and excited states are shown to have angular momenta that are different from the eigenvalues of the usual quantum mechanical operators. The uncertainty relations are found not to be applicable to the orthogonal components of the angular momentum. No double electron spin gyromagnetic ratio is required to account for the observed magnetic moments, and the behavior of the atom in a magnetic field is described entirely in kinetic terms.
2011-07-26
... COMMISSION Atomic Safety and Licensing Board; In the Matter of Nuclear Innovation North America LLC (South... portion of this proceeding regarding the application of Nuclear Innovation North America LLC (NINA) for... and Economic Development Coalition, the South Texas Association for Responsible Energy, and...
2013-11-13
... COMMISSION Atomic Safety and Licensing Board; In the Matter of Nuclear Innovation North America LLC (South... application of Nuclear Innovation North America LLC (NINA) for combined licenses that would authorize NINA to.../reactors/new-reactors/col/south-texas-project.html . These and other documents relating to this...
Turkmen, Hakan; Buyukaltay, Didem
2015-01-01
In this study, the effect of using Jigsaw II and Jigsaw IV techniques on the subject of "Atoms-The Basic Unit of Matter" in science course of 6th grade on academic achievement was examined. Pre-test post-test control group research was used in the study. Study population is all secondary schools in Turgutlu district of Manisa province…
Gravitational Waves as a New Probe of Bose-Einstein Condensate Dark Matter
Dev, P S Bhupal; Ohmer, Sebastian
2016-01-01
There exists a class of ultralight Dark Matter (DM) models which could form a Bose-Einstein condensate (BEC) in the early universe and behave as a single coherent wave instead of individual particles in galaxies. We show that a generic BEC DM halo intervening along the line of sight of a gravitational wave (GW) signal could induce an observable change in the speed of GW, with the effective refractive index depending only on the mass and self-interaction of the constituent DM particles and the GW frequency. Hence, we propose to use the deviation in the speed of GW as a new probe of the BEC DM parameter space. With a multi-messenger approach to GW astronomy and/or with extended sensitivity to lower GW frequencies, the entire BEC DM parameter space can be effectively probed by our new method in the near future.
Field theory for zero sound and ion acoustic wave in astrophysical matter
Gabadadze, Gregory; Rosen, Rachel A.
2016-02-01
We set up a field theory model to describe the longitudinal low-energy modes in high density matter present in white dwarf stars. At the relevant scales, ions—the nuclei of oxygen, carbon, and helium—are treated as heavy pointlike spin-0 charged particles in an effective field theory approach, while the electron dynamics is described by the Dirac Lagrangian at the one-loop level. We show that there always exists a longitudinal gapless mode in the system irrespective of whether the ions are in a plasma, crystal, or quantum liquid state. For certain values of the parameters, the gapless mode can be interpreted as a zero sound mode and, for other values, as an ion acoustic wave; we show that the zero sound and ion acoustic wave are complementary to each other. We discuss possible physical consequences of these modes for properties of white dwarfs.
Field Theory for Zero Sound and Ion Acoustic Wave in Astrophysical Matter
Gabadadze, Gregory
2015-01-01
We set up a field theory model to describe the longitudinal low energy modes in high density matter present in white dwarf stars. At the relevant scales, ions -- the nuclei of oxygen, carbon and helium -- are treated as heavy point-like spin-0 charged particles in an effective field theory approach, while the electron dynamics is described by the Dirac Lagrangian at the one-loop level. We show that there always exists a longitudinal gapless mode in the system irrespective whether the ions are in a plasma, crystal, or quantum liquid state. For certain values of the parameters, the gapless mode can be interpreted as a zero sound mode and, for other values, as an ion acoustic wave; we show that the zero sound and ion acoustic wave are complementary to each other. We discuss possible physical consequences of these modes for properties of white dwarfs.
Non-autonomous bright matter wave solitons in spinor Bose–Einstein condensates
International Nuclear Information System (INIS)
We investigate the dynamics of bright matter wave solitons in spin-1 Bose–Einstein condensates with time modulated nonlinearities. We obtain soliton solutions of an integrable autonomous three-coupled Gross–Pitaevskii (3-GP) equations using Hirota's method involving a non-standard bilinearization. The similarity transformations are developed to construct the soliton solutions of non-autonomous 3-GP system. The non-autonomous solitons admit different density profiles. An interesting phenomenon of soliton compression is identified for kink-like nonlinearity coefficient with Hermite–Gaussian-like potential strength. Our study shows that these non-autonomous solitons undergo non-trivial collisions involving condensate switching
Non-autonomous bright matter wave solitons in spinor Bose–Einstein condensates
Energy Technology Data Exchange (ETDEWEB)
Kanna, T., E-mail: kanna_phy@bhc.edu.in; Babu Mareeswaran, R.; Sakkaravarthi, K.
2014-01-10
We investigate the dynamics of bright matter wave solitons in spin-1 Bose–Einstein condensates with time modulated nonlinearities. We obtain soliton solutions of an integrable autonomous three-coupled Gross–Pitaevskii (3-GP) equations using Hirota's method involving a non-standard bilinearization. The similarity transformations are developed to construct the soliton solutions of non-autonomous 3-GP system. The non-autonomous solitons admit different density profiles. An interesting phenomenon of soliton compression is identified for kink-like nonlinearity coefficient with Hermite–Gaussian-like potential strength. Our study shows that these non-autonomous solitons undergo non-trivial collisions involving condensate switching.
Olofson, Frans; Holmlid, Leif
2010-01-01
A material exists which links together the influx of meteoritic matter from interplanetary space, the polar mesosphere summer echoes (PMSE), the sporadic sodium layers, the polar mesospheric clouds (PMCs, NLCs), and the observed ion chemistry in the mesosphere. The evidence in these research fields is here analyzed and found to agree well with the properties of Rydberg Matter (RM). This material has been studied with numerous methods in the laboratory. Alkali atoms, mainly Na, reach the mesosphere in the form of interplanetary (meteoritic, cometary) dust. The planar RM clusters NaN usually contain N = 19, 37 or 61 atoms, and have the density of air at 90 km altitude where they float. The diameters of the clusters are 10-100 nm from laboratory high precision radio frequency spectroscopic studies. Such experiments show that RM clusters interact strongly with radar frequencies: this explains the radio frequency heating and reflection studies of PMSE layers. The clusters give the low temperature in the mesosphere...
Demonstration of a Sagnac-Type Cold Atom Interferometer with Stimulated Raman Transitions
Institute of Scientific and Technical Information of China (English)
WANG Ping; LI Run-Bing; YAN Hui; WANG Jin; ZHAN Ming-Sheng
2007-01-01
@@ Cold-matter-wave Sagnac interferometers possess many advantages over their thermal atomic beam counterparts when they are used as precise inertial sensors. We report a realization of a Sagnac-type interferometer with cold atoms.
Aramaki, T; Craig, W W; Fabris, L; Gahbauer, F; Hailey, C J; Koglin, J E; Madden, N; Mori, K; Yu, H T; Ziock, K P
2013-01-01
The General AntiParticle Spectrometer (GAPS) is a novel approach for indirect dark matter searches that exploits cosmic antideuterons. GAPS utilizes a distinctive detection method using atomic X-rays and charged particles from the exotic atom as well as the timing, stopping range and dE/dX energy deposit of the incoming particle, which provides excellent antideuteron identification. Prior to the future balloon experiment, an accelerator test was conducted in 2004 and 2005 at KEK, Japan, in order to precisely measure the X-ray yields of antiprotonic exotic atoms formed with different target materials. The X-ray yields of the exotic atoms with Al and S targets were obtained as $\\sim$ 75%, which are higher than were previously assumed in. A simple, but comprehensive cascade model has been developed not only to evaluate the measurement results but also to predict the X-ray yields of the exotic atoms formed with any materials in the GAPS instrument. The cascade model is extendable to any kind of exotic atom (any n...
Institute of Scientific and Technical Information of China (English)
刘洪毓
2007-01-01
Atoms(原子)are all around us.They are something like the bricks (砖块)of which everything is made. The size of an atom is very,very small.In just one grain of salt are held millions of atoms. Atoms are very important.The way one object acts depends on what
Black holes and gravitational waves in models of minicharged dark matter
Cardoso, Vitor; Pani, Paolo; Ferrari, Valeria
2016-01-01
In viable models of minicharged dark matter, astrophysical black holes might be charged under a hidden $U(1)$ symmetry and are formally described by the same Kerr-Newman solution of Einstein-Maxwell theory. These objects are unique probes of minicharged dark matter and dark photons. We show that the recent gravitational-wave detection of a binary black-hole coalescence by aLIGO provides various observational bounds on the black hole's charge, regardless of its nature. The pre-merger inspiral phase can be used to constrain the dipolar emission of (ordinary and dark) photons, whereas the detection of the quasinormal modes set an upper limit on the final black hole's charge. By using a toy model of a point charge plunging into a Reissner-Nordstrom black hole, we also show that in dynamical processes the (hidden) electromagnetic quasinormal modes of the final object are excited to considerable amplitude in the gravitational-wave spectrum only when the black hole is nearly extremal. The coalescence produces a burs...
Black holes and gravitational waves in models of minicharged dark matter
Cardoso, Vitor; Macedo, Caio F. B.; Pani, Paolo; Ferrari, Valeria
2016-05-01
In viable models of minicharged dark matter, astrophysical black holes might be charged under a hidden U(1) symmetry and are formally described by the same Kerr-Newman solution of Einstein-Maxwell theory. These objects are unique probes of minicharged dark matter and dark photons. We show that the recent gravitational-wave detection of a binary black-hole coalescence by aLIGO provides various observational bounds on the black hole's charge, regardless of its nature. The pre-merger inspiral phase can be used to constrain the dipolar emission of (ordinary and dark) photons, whereas the detection of the quasinormal modes set an upper limit on the final black hole's charge. By using a toy model of a point charge plunging into a Reissner-Nordstrom black hole, we also show that in dynamical processes the (hidden) electromagnetic quasinormal modes of the final object are excited to considerable amplitude in the gravitational-wave spectrum only when the black hole is nearly extremal. The coalescence produces a burst of low-frequency dark photons which might provide a possible electromagnetic counterpart to black-hole mergers in these scenarios.
Kumar, Parvendra; Sarma, Amarendra K.
2011-01-01
We report a study on light force on a beam of neutral two-level atoms superimposed upon a few-cycle pulsed Gaussian laser field under both resonant and off-resonant condition. The phenomena of focusing, defocusing and steering of the neutral atoms in the laser field is analysed by solving the optical Bloch equation beyond the rotating wave approximation and the force equation self-consistently .We find that two-level atoms in an atomic beam could be focused and defocused for large, positively...
Bender, Peter L.
2015-08-01
1. In 2013 a suggestion was made by Graham et al. [1] [Phys. Rev. Lett. 110, 171102 (2013)] of possible GW observations over 10^3 km baselines using strongly forbidden single photon transitions in atoms such as Sr-87. A comparison of the requirements for such a mission with those for laser interferometer missions such as LISA or eLISA with roughly 10^6 km baselines was published in 2014 [Bender, Phys. Rev. D 89, 062004 (2014)]. The comparison will be somewhat updated in this talk.2. Recently, a possible method for gravitational wave observations with atom interferometry over million km scale baselines has been suggested by Hogan and Kasevich [arXiv:1501.06797v1 (2015)]. As an example, they consider observations similar to those discussed in [1], but over a 2*10^6 km baseline. The atomic transitions in the two spacecraft would be driven by separate lasers that are phase locked using 1 W laser power and 30 cm diam. telescopes. Total observation times for individual clouds of 80 to 320 s are assumed, along with 50 concurrent interferometers and a 60 Hz Rabi frequency for the laser pulses.3. After the flight of the LISA Pathfinder mission later this year, it is expected that more intensive work will start on a laser interferometer gravitational wave mission. Probably the most important objective will be the observation of GW signals from the mergers at high redshifts of massive black holes with masses in the range from perhaps 10^4 to 10^7 M_sun. Such signals would give new constraints on the mechanisms for the formation of intermediate mass and larger black holes at early times, and probably contribute to understanding the observed close correlation between the growth of galaxies and of the massive black holes at their centers.
Lemeshko, Mikhail
2008-01-01
We investigate the effects of a magnetic field on the dynamics of rotationally inelastic collisions of open-shell molecules ($^2\\Sigma$, $^3\\Sigma$, and $^2\\Pi$) with closed-shell atoms. Our treatment makes use of the Fraunhofer model of matter wave scattering and its recent extension to collisions in electric [M. Lemeshko and B. Friedrich, J. Chem. Phys. \\textbf{129}, 024301 (2008)] and radiative fields [M. Lemeshko and B. Friedrich, Int. J. Mass. Spec. in press (2008)]. A magnetic field aligns the molecule in the space-fixed frame and thereby alters the effective shape of the diffraction target. This significantly affects the differential and integral scattering cross sections. We exemplify our treatment by evaluating the magnetic-field-dependent scattering characteristics of the He -- CaH ($X ^2\\Sigma^+$), He -- O$_2$ ($X ^3\\Sigma^-$) and He -- OH ($X ^2\\Pi_{\\Omega}$) systems at thermal collision energies. Since the cross sections can be obtained for different orientations of the magnetic field with respec...
Low Frequency Gravitational Wave Detection With Ground Based Atom Interferometer Arrays
Chaibi, W; Canuel, B; Bertoldi, A; Landragin, A; Bouyer, P
2016-01-01
We propose a new detection strategy for gravitational waves (GWs) below few Hertz based on a correlated array of atom interferometers (AIs). Our proposal allows to reduce the Newtonian Noise (NN) which limits all ground based GW detectors below few Hertz, including previous atom interferometry-based concepts. Using an array of long baseline AI gradiometers yields several estimations of the NN, whose effect can thus be reduced via statistical averaging. Considering the km baseline of current optical detectors, a NN rejection of factor 2 could be achieved, and tested with existing AI array geometries. Exploiting the correlation properties of the gravity acceleration noise, we show that a 10-fold or more NN rejection is possible with a dedicated configuration. Considering a conservative NN model and the current developments in cold atom technology, we show that strain sensitivities below $1\\times 10^{-19}/ \\sqrt{\\text{Hz}}$ in the $ 0.3-3 \\ \\text{Hz}$ frequency band can be within reach, with a peak sensitivity o...
Low frequency gravitational wave detection with ground-based atom interferometer arrays
Chaibi, W.; Geiger, R.; Canuel, B.; Bertoldi, A.; Landragin, A.; Bouyer, P.
2016-01-01
We propose a new detection strategy for gravitational waves (GWs) below a few hertz based on a correlated array of atom interferometers (AIs). Our proposal allows us to reduce the Newtonian noise (NN), which limits all ground based GW detectors below a few hertz, including previous atom interferometry-based concepts. Using an array of long baseline AI gradiometers yields several estimations of the NN, whose effect can thus be reduced via statistical averaging. Considering the km baseline of current optical detectors, a NN rejection of a factor of 2 could be achieved and tested with existing AI array geometries. Exploiting the correlation properties of the gravity acceleration noise, we show that a tenfold or more NN rejection is possible with a dedicated configuration. Considering a conservative NN model and the current developments in cold atom technology, we show that strain sensitivities below 1 ×10-19/√{Hz } in the 0.3 -3 Hz frequency band can be within reach, with a peak sensitivity of 3 ×10-23/√{Hz } at 2 Hz . Our proposed configuration could extend the observation window of current detectors by a decade and fill the gap between ground-based and space-based instruments.
A compact micro-wave synthesizer for transportable cold-atom interferometers
International Nuclear Information System (INIS)
We present the realization of a compact micro-wave frequency synthesizer for an atom interferometer based on stimulated Raman transitions, applied to transportable inertial sensing. Our set-up is intended to address the hyperfine transitions of 87Rb at 6.8 GHz. The prototype is evaluated both in the time and the frequency domain by comparison with state-of-the-art frequency references developed at Laboratoire national de métrologie et d'essais−Systémes de référence temps espace (LNE-SYRTE). In free-running mode, it features a residual phase noise level of −65 dB rad2 Hz−1 at 10 Hz offset frequency and a white phase noise level in the order of −120 dB rad2 Hz−1 for Fourier frequencies above 10 kHz. The phase noise effect on the sensitivity of the atomic interferometer is evaluated for diverse values of cycling time, interrogation time, and Raman pulse duration. To our knowledge, the resulting contribution is well below the sensitivity of any demonstrated cold atom inertial sensors based on stimulated Raman transitions. The drastic improvement in terms of size, simplicity, and power consumption paves the way towards field and mobile operations
International Nuclear Information System (INIS)
Completed by recent contributions on various topics (atoms and the Brownian motion, the career of Jean Perrin, the evolution of atomic physics since Jean Perrin, relationship between scientific atomism and philosophical atomism), this book is a reprint of a book published at the beginning of the twentieth century in which the author addressed the relationship between atomic theory and chemistry (molecules, atoms, the Avogadro hypothesis, molecule structures, solutes, upper limits of molecular quantities), molecular agitation (molecule velocity, molecule rotation or vibration, molecular free range), the Brownian motion and emulsions (history and general features, statistical equilibrium of emulsions), the laws of the Brownian motion (Einstein's theory, experimental control), fluctuations (the theory of Smoluchowski), light and quanta (black body, extension of quantum theory), the electricity atom, the atom genesis and destruction (transmutations, atom counting)
Atomization off thin water films generated by high-frequency substrate wave vibrations
Collins, David J.; Manor, Ofer; Winkler, Andreas; Schmidt, Hagen; Friend, James R.; Yeo, Leslie Y.
2012-11-01
Generating aerosol droplets via the atomization of thin aqueous films with high frequency surface acoustic waves (SAWs) offers several advantages over existing nebulization methods, particularly for pulmonary drug delivery, offering droplet sizes in the 1-5-μm range ideal for effective pulmonary therapy. Nevertheless, the physics underlying SAW atomization is not well understood, especially in the context of thin liquid film formation and spreading and how this affects the aerosol production. Here, we demonstrate that the film geometry, governed primarily by the applied power and frequency of the SAW, indeed plays a crucial role in the atomization process and, in particular, the size of the atomized droplets. In contrast to the continuous spreading of low surface energy liquids atop similar platforms, high surface energy liquids such as water, in the present case, are found to undergo transient spreading due to the SAW to form a quasisteady film whose height is determined by self-selection of the energy minimum state associated with the acoustic resonance in the film and whose length arises from a competition between acoustic streaming and capillary effects. This is elucidated from a fundamental model for the thin film spreading behavior under SAW excitation, from which we show good agreement between the experimentally measured and theoretically predicted droplet dimension, both of which consistently indicate a linear relationship between the droplet diameter and the mechanical power coupled into the liquid by the SAW (the latter captured by an acoustic Weber number to the two thirds power, and the reciprocal of the SAW frequency).
Snapshots of cooperative atomic motions in the optical suppression of charge density waves.
Eichberger, Maximilian; Schäfer, Hanjo; Krumova, Marina; Beyer, Markus; Demsar, Jure; Berger, Helmuth; Moriena, Gustavo; Sciaini, Germán; Miller, R J Dwayne
2010-12-01
Macroscopic quantum phenomena such as high-temperature superconductivity, colossal magnetoresistance, ferrimagnetism and ferromagnetism arise from a delicate balance of different interactions among electrons, phonons and spins on the nanoscale. The study of the interplay among these various degrees of freedom in strongly coupled electron-lattice systems is thus crucial to their understanding and for optimizing their properties. Charge-density-wave (CDW) materials, with their inherent modulation of the electron density and associated periodic lattice distortion, represent ideal model systems for the study of such highly cooperative phenomena. With femtosecond time-resolved techniques, it is possible to observe these interactions directly by abruptly perturbing the electronic distribution while keeping track of energy relaxation pathways and coupling strengths among the different subsystems. Numerous time-resolved experiments have been performed on CDWs, probing the dynamics of the electronic subsystem. However, the dynamics of the periodic lattice distortion have been only indirectly inferred. Here we provide direct atomic-level information on the structural dynamics by using femtosecond electron diffraction to study the quasi two-dimensional CDW system 1T-TaS(2). Effectively, we have directly observed the atomic motions that result from the optically induced change in the electronic spatial distribution. The periodic lattice distortion, which has an amplitude of ∼0.1 Å, is suppressed by about 20% on a timescale (∼250 femtoseconds) comparable to half the period of the corresponding collective mode. These highly cooperative, electronically driven atomic motions are accompanied by a rapid electron-phonon energy transfer (∼350 femtoseconds) and are followed by fast recovery of the CDW (∼4 picoseconds). The degree of cooperativity in the observed structural dynamics is remarkable and illustrates the importance of obtaining atomic-level perspectives of the
Geiger, R; Bertoldi, A; Canuel, B; Chaibi, W; Danquigny, C; Dutta, I; Fang, B; Gaffet, S; Gillot, J; Holleville, D; Landragin, A; Merzougui, M; Riou, I; Savoie, D; Bouyer, P
2015-01-01
The MIGA project aims at demonstrating precision measurements of gravity with cold atom sensors in a large scale instrument and at studying the associated powerful applications in geosciences and fundamental physics. The firt stage of the project (2013-2018) will consist in building a 300-meter long optical cavity to interrogate atom interferometers and will be based at the low noise underground laboratory LSBB based in Rustrel, France. The second stage of the project (2018-2023) will be dedicated to science runs and data analyses in order to probe the spatio-temporal structure of the local gravity field of the LSBB region, which represents a generic site of hydrological interest. MIGA will also assess future potential applications of atom interferometry to gravitational wave detection in the frequency band 0.1-10 Hz hardly covered by future long baseline optical interferometers. This paper presents the main objectives of the project, the status of the construction of the instrument and the motivation for the...
Stadnik, Y. V.; Flambaum, V. V.
2015-01-01
We present an overview of recent developments in the detection of light bosonic dark matter, including axion, pseudoscalar axion-like and scalar dark matter, which form either a coherently oscillating classical field or topological defects (solitons). We emphasise new high-precision laboratory and astrophysical measurements, in which the sought effects are linear in the underlying interaction strength between dark matter and ordinary matter, in contrast to traditional detection schemes for da...
Enhanced harmonic generation and wave-mixing via two-color multiphoton excitation of atoms/molecules
Avetissian, H K; Mkrtchian, G F
2016-01-01
We consider harmonics generation and wave-mixing by two-color multi photon resonant excitation of three-level atoms/molecules in strong laser fields. The coherent part of the spectra corresponding to multicolor harmonics generation is investigated. The obtained analytical results on the basis of generalized rotating wave approximation are in a good agreement with numerical calculations. The results applied to the hydrogen atom and homonuclear diatomic molecular ion show that one can achieve efficient generation of moderately high multicolor harmonics via multiphoton resonant excitation by appropriate laser pulses.
Institute of Scientific and Technical Information of China (English)
LI Yuan-Yuan; BAI Jin-Wao; LI-Li; ZHANG Wei-Feng; LI Chang-Biao; NIE Zhi-Qiang; GAN Chen-Li; ZHANG Yan-Peng
2008-01-01
Dicke-narrowing effect appears both in doubly dressed electromagnetically induced transparency and singly dressed four-wave-mixing lines due to the contribution of slow atoms resulting from de-excited effects of atom-wall collision and transient behaviour of atoms in a confined system. A robust recipe for high resolution spectroscopy of electromagnetically induced transparency dressed by two fields and four-wave-mixing lines comparable with the cold atoms is achievable in a thin vapour cell in experiments.
A projection-free method for representing plane-wave DFT results in an atom-centered basis
International Nuclear Information System (INIS)
Plane wave density functional theory (DFT) is a powerful tool for gaining accurate, atomic level insight into bulk and surface structures. Yet, the delocalized nature of the plane wave basis set hinders the application of many powerful post-computation analysis approaches, many of which rely on localized atom-centered basis sets. Traditionally, this gap has been bridged via projection-based techniques from a plane wave to atom-centered basis. We instead propose an alternative projection-free approach utilizing direct calculation of matrix elements of the converged plane wave DFT Hamiltonian in an atom-centered basis. This projection-free approach yields a number of compelling advantages, including strict orthonormality of the resulting bands without artificial band mixing and access to the Hamiltonian matrix elements, while faithfully preserving the underlying DFT band structure. The resulting atomic orbital representation of the Kohn-Sham wavefunction and Hamiltonian provides a gateway to a wide variety of analysis approaches. We demonstrate the utility of the approach for a diverse set of chemical systems and example analysis approaches
Three-body bound states in atomic mixtures with resonant p-wave interaction
Efremov, Maxim A; Ivanov, Misha Yu; Schleich, Wolfgang P
2013-01-01
We employ the Born-Oppenheimer approximation to find the effective potential in a three-body system consisting of a light particle and two heavy ones when the heavy-light short-range interaction potential has a resonance corresponding to a non-zero orbital angular momentum. In the case of an exact resonance in the p-wave scattering amplitude, the effective potential is attractive and long-range, namely it decreases as the third power of the inter-atomic distance. Moreover, we show that the range and power of the potential, as well as the number of bound states are determined by the mass ratio of the particles and the parameters of the heavy-light short-range potential.
Continuous-wave, single-frequency 229 nm laser source for laser cooling of cadmium atoms
Kaneda, Yushi; Merzlyak, Yevgeny; Yamaguchi, Atsushi; Hayashida, Keitaro; Ohmae, Noriaki; Katori, Hidetoshi
2016-01-01
Continuous-wave output at 229 nm for the application of laser cooling of Cd atoms was generated by the 4th harmonic using two successive second harmonic generation stages. Employing a single-frequency optically pumped semiconductor laser as a fundamental source, 0.56 W of output at 229 nm was observed with a 10-mm long, Brewster-cut BBO crystal in an external cavity with 1.62 W of 458 nm input. Conversion efficiency from 458 nm to 229 nm was more than 34%. By applying a tapered amplifier as a fundamental source, we demonstrated magneto-optical trapping of all stable Cd isotopes including isotopes $^{111}$Cd and $^{113}$Cd, which are applicable to optical lattice clocks.
Atomic displacements in the incommensurable charge-density wave in alpha-uranium
International Nuclear Information System (INIS)
A detailed examination is presented of the incommensurable charge-density wave (ICDW) in α-uranium below 43K. The q vectors have been measured as a function of temperature and the structure factors of a large number of first-order satellites with neutron diffraction. From the structure factors the atomic displacements that occur at the onset of the CDW have been determined in all three independent crystallographic directions. Uniaxial stress up to 3.5kbar has been applied along 2 directions but does not change the satellite intensities, thus leaving ambiguity whether the structure is single or multi q. The relationship between the present results and the observations of Smith et al is discussed. (author)
Indian Academy of Sciences (India)
Pier A Mello
2001-02-01
Universal statistical aspects of wave scattering by a variety of physical systems ranging from atomic nuclei to mesoscopic systems and microwave cavities are described. A statistical model for the scattering matrix is employed to address the problem of quantum chaotic scattering. The model, introduced in the past in the context of nuclear physics, discusses the problem in terms of a prompt and an equilibrated component: it incorporates the average value of the scattering matrix to account for the prompt processes and satisﬁes the requirements of ﬂux conservation, causality and ergodicity. The main application of the model is the analysis of electronic transport through ballistic mesoscopic cavities: it describes well the results from the numerical solutions of the Schrödinger equation for two-dimensional cavities.
Barenboim, Gabriela
2016-01-01
We investigate the gravitational wave background from a first order phase transition in a matter-dominated universe, and show that it has a unique feature from which important information about the properties of the phase transition and thermal history of the universe can be easily extracted. Also, we discuss the inverse problem of such a gravitational wave background in view of the degeneracy among macroscopic parameters governing the signal.
Corda, Christian
2012-01-01
Towards the goal to quantize gravity, in this short review we discuss an intermediate step which consists in extending the picture of standard General Relativity by considering Extended Theories of Gravity. In this tapestry, the equations to quantize are not the standard Einstein field equations of General Relativity, but the extended Einstein field equations of such Extended Theories. The traditional relation between mass-energy and space-time curvature, which founds standard General Relativity, results modified in this new picture and, at least at the linearized approximation, variations of the space-time curvature generate the mass-energy. Various problems of the Dark Universe, Dark Energy, Dark Matter and Pioneer anomaly, can be, in principle, solved through this approach, while a definitive endorsement for Extended Theories of Gravity could arrive from the realization of a consistent gravitational wave astronomy. We also discuss the quantization of both mass-energy and space-time curvature in the early U...
A gravitational shock wave generated by a beam of null matter in quadratic gravity
International Nuclear Information System (INIS)
In the present work we approximate an ultrarelativistic jet by a homogeneous beam of null matter with finite width. Then, we study the influence of this beam over the spacetime metric in the framework of higher-derivative gravity. We find an exact shock wave solution of the quadratic gravity field equations and compare it with the solution to Einstein's gravity. We show that the effect of higher-curvature gravity becomes negligible at large distances from the beam axis. We also observe that only the Ricci-squared term contribute to modify the Einstein's gravity prediction. Furthermore, we note that this higher-curvature term contributes to regularize the discontinuities associated with the solution to Einstein's general relativity
Absolute Absorption Cross Sections from Photon Recoil in a Matter-Wave Interferometer
Eibenberger, Sandra; Cheng, Xiaxi; Cotter, J. P.; Arndt, Markus
2014-06-01
We measure the absolute absorption cross section of molecules using a matter-wave interferometer. A nanostructured density distribution is imprinted onto a dilute molecular beam through quantum interference. As the beam crosses the light field of a probe laser some molecules will absorb a single photon. These absorption events impart a momentum recoil which shifts the position of the molecule relative to the unperturbed beam. Averaging over the shifted and unshifted components within the beam leads to a reduction of the fringe visibility, enabling the absolute absorption cross section to be extracted with high accuracy. This technique is independent of the molecular density, it is minimally invasive and successfully eliminates many problems related to photon cycling, state mixing, photobleaching, photoinduced heating, fragmentation, and ionization. It can therefore be extended to a wide variety of neutral molecules, clusters, and nanoparticles.
Absolute absorption cross sections from photon recoil in a matter-wave interferometer
Eibenberger, Sandra; Cotter, J P; Arndt, Markus
2014-01-01
We measure the absolute absorption cross section of molecules using a matter-wave interferometer. A nanostructured density distribution is imprinted onto a dilute molecular beam through quantum interference. As the beam crosses the light field of a probe laser some molecules will absorb a single photon. These absorption events impart a momentum recoil which shifts the position of the molecule relative to the unperturbed beam. Averaging over the shifted and unshifted components within the beam leads to a reduction of the fringe visibility, enabling the absolute absorption cross section to be extracted with high accuracy. This technique is independent of the molecular density, it is minimally invasive and successfully eliminates all problems related to photon-cycling, state-mixing, photo-bleaching, photo-induced heating, fragmentation and ionization. It can therefore be extended to a wide variety of neutral molecules, clusters and nanoparticles.
Matter-wave two-dimensional solitons in crossed linear and nonlinear optical lattices
International Nuclear Information System (INIS)
The existence of multidimensional matter-wave solitons in a crossed optical lattice (OL) with a linear optical lattice (LOL) in the x direction and a nonlinear optical lattice (NOL) in the y direction, where the NOL can be generated by a periodic spatial modulation of the scattering length using an optically induced Feshbach resonance is demonstrated. In particular, we show that such crossed LOLs and NOLs allow for stabilizing two-dimensional solitons against decay or collapse for both attractive and repulsive interactions. The solutions for the soliton stability are investigated analytically, by using a multi-Gaussian variational approach, with the Vakhitov-Kolokolov necessary criterion for stability; and numerically, by using the relaxation method and direct numerical time integrations of the Gross-Pitaevskii equation. Very good agreement of the results corresponding to both treatments is observed.
Matter-wave two-dimensional solitons in crossed linear and nonlinear optical lattices
da Luz, H. L. F.; Abdullaev, F. Kh.; Gammal, A.; Salerno, M.; Tomio, Lauro
2010-10-01
The existence of multidimensional matter-wave solitons in a crossed optical lattice (OL) with a linear optical lattice (LOL) in the x direction and a nonlinear optical lattice (NOL) in the y direction, where the NOL can be generated by a periodic spatial modulation of the scattering length using an optically induced Feshbach resonance is demonstrated. In particular, we show that such crossed LOLs and NOLs allow for stabilizing two-dimensional solitons against decay or collapse for both attractive and repulsive interactions. The solutions for the soliton stability are investigated analytically, by using a multi-Gaussian variational approach, with the Vakhitov-Kolokolov necessary criterion for stability; and numerically, by using the relaxation method and direct numerical time integrations of the Gross-Pitaevskii equation. Very good agreement of the results corresponding to both treatments is observed.
Generation of single photons with highly tunable wave shape from a cold atomic quantum memory
Farrera, Pau; Albrecht, Boris; Ho, Melvyn; Chávez, Matías; Teo, Colin; Sangouard, Nicolas; de Riedmatten, Hugues
2016-01-01
We report on a single photon source with highly tunable photon shape based on a cold ensemble of Rubidium atoms. We follow the DLCZ scheme to implement an emissive quantum memory, which can be operated as a photon pair source with controllable delay. We find that the temporal wave shape of the emitted read photon can be precisely controlled by changing the shape of the driving read pulse. We generate photons with temporal durations varying over three orders of magnitude up to 10 {\\mu}s without a significant change of the read-out efficiency. We prove the non-classicality of the emitted photons by measuring their antibunching, showing near single photon behavior at low excitation probabilities. We also show that the photons are emitted in a pure state by measuring unconditional autocorrelation functions. Finally, to demonstrate the usability of the source for realistic applications, we create ultra-long single photons with a rising exponential or doubly peaked wave shape which are important for several quantum...
International Nuclear Information System (INIS)
For systems of interacting, ultracold spin-zero neutral bosonic atoms, harmonically trapped and subject to an optical lattice potential, we derive an Extended Bose Hubbard (EBH) model by developing a systematic expansion for the Hamiltonian of the system in powers of the lattice parameters and of a scale parameter, the lattice attenuation factor. We identify the dominant terms that need to be retained in realistic experimental conditions, up to nearest-neighbor interactions and nearest-neighbor hoppings conditioned by the on-site occupation numbers. In the mean field approximation, we determine the free energy of the system and study the phase diagram both at zero and at finite temperature. At variance with the standard on site Bose Hubbard model, the zero-temperature phase diagram of the EBH model possesses a dual structure in the Mott insulating regime. Namely, for specific ranges of the lattice parameters, a density wave phase characterizes the system at integer fillings, with domains of alternating mean occupation numbers that are the atomic counterparts of the domains of staggered magnetizations in an antiferromagnetic phase. We show as well that in the EBH model, a zero-temperature quantum phase transition to pair superfluidity is, in principle, possible, but completely suppressed at the lowest order in the lattice attenuation factor. Finally, we determine the possible occurrence of the different phases as a function of the experimentally controllable lattice parameters
Dressed Gain from the Parametrically Amplified Four-Wave Mixing Process in an Atomic Vapor
Zhang, Zhaoyang; Wen, Feng; Che, Junling; Zhang, Dan; Li, Changbiao; Zhang, Yanpeng; Xiao, Min
2015-10-01
With a forward cone emitting from the strong pump laser in a thermal rubidium atomic vapor, we investigate the non-degenerate parametrically amplified four-wave mixing (PA-FWM) process with dressing effects in a three-level “double-Λ” configuration both theoretically and experimentally. By seeding a weak probe field into the Stokes or anti-Stokes channel of the FWM, the gain processes are generated in the bright twin beams which are called conjugate and probe beams, respectively. However, the strong dressing effect of the pump beam will dramatically affect the gain factors both in the probe and conjugate channels, and can inevitably impose an influence on the quantum effects such as entangled degree and the quantum noise reduction between the two channels. We systematically investigate the intensity evolution of the dressed gain processes by manipulating the atomic density, the Rabi frequency and the frequency detuning. Such dressing effects are also visually evidenced by the observation of Autler-Townes splitting of the gain peaks. The investigation can contribute to the development of quantum information processing and quantum communications.
Hees, A; Guéna, J; Abgrall, M; Bize, S; Wolf, P
2016-08-01
We use 6 yrs of accurate hyperfine frequency comparison data of the dual rubidium and caesium cold atom fountain FO2 at LNE-SYRTE to search for a massive scalar dark matter candidate. Such a scalar field can induce harmonic variations of the fine structure constant, of the mass of fermions, and of the quantum chromodynamic mass scale, which will directly impact the rubidium/caesium hyperfine transition frequency ratio. We find no signal consistent with a scalar dark matter candidate but provide improved constraints on the coupling of the putative scalar field to standard matter. Our limits are complementary to previous results that were only sensitive to the fine structure constant and improve them by more than an order of magnitude when only a coupling to electromagnetism is assumed. PMID:27541455
Hees, A; Abgrall, M; Bize, S; Wolf, P
2016-01-01
We use six years of accurate hyperfine frequency comparison data of the dual Rubidium and Caesium cold atom fountain FO2 at LNE-SYRTE to search for a massive scalar dark matter candidate. Such a scalar field can induce harmonic variations of the fine structure constant, of the mass of fermions and of the quantum chromodynamic mass scale, which will directly impact the Rubidium/Caesium hyperfine transition frequency ratio. We find no signal consistent with a scalar dark matter candidate but provide improved constraints on the coupling of the putative scalar field to standard matter. Our limits are complementary to previous results that were only sensitive to the fine-structure constant, and improve them by more than an order of magnitude when only a coupling to electromagnetism is assumed.
Chen, Jiunn-Wei; Chi, Hsin-Chang; Lin, Shin-Ted; Liu, C.-P.; Singh, Lakhwinder; Wong, Henry T.; Wu, Chih-Liang; Wu, Chih-Pan
2016-05-01
The transition magnetic moment of a sterile neutrino can give rise to its conversion to an active neutrino through radiative decay or nonstandard interaction (NSI) with matter. For sterile neutrinos of keV-mass as dark matter candidates, their decay signals are actively searched for in cosmic x-ray spectra. In this work, we consider the NSI that leads to atomic ionization, which can be detected by direct dark matter experiments. It is found that this inelastic scattering process for a nonrelativistic sterile neutrino has a pronounced enhancement in the differential cross section at energy transfer about half of its mass, manifesting experimentally as peaks in the measurable energy spectra. The enhancement effects gradually smear out as the sterile neutrino becomes relativistic. Using data taken with low-threshold low-background germanium detectors, constraints on sterile neutrino mass and its transition magnetic moment are derived and compared with those from astrophysical observations.
Hees, A.; Guéna, J.; Abgrall, M.; Bize, S.; Wolf, P.
2016-08-01
We use 6 yrs of accurate hyperfine frequency comparison data of the dual rubidium and caesium cold atom fountain FO2 at LNE-SYRTE to search for a massive scalar dark matter candidate. Such a scalar field can induce harmonic variations of the fine structure constant, of the mass of fermions, and of the quantum chromodynamic mass scale, which will directly impact the rubidium/caesium hyperfine transition frequency ratio. We find no signal consistent with a scalar dark matter candidate but provide improved constraints on the coupling of the putative scalar field to standard matter. Our limits are complementary to previous results that were only sensitive to the fine structure constant and improve them by more than an order of magnitude when only a coupling to electromagnetism is assumed.
Probing the properties of quantum matter; an experimental study in three parts using ultracold atoms
Bons, P.C.
2015-01-01
The three experiments described in this thesis investigate fundamental properties of ultracold atoms. Using laser cooling and evaporative cooling, a dilute gas of sodium atoms is cooled to ~100 nK. Under these circumstances a Bose-Einstein condensate (BEC) forms, where millions of atoms collapse into the lowest energy state of the system and share a macroscopic wavefunction. The experiments are done in an ultrahigh vacuum and the atoms are manipulated remotely using laser beams, magnetic fiel...
Stolz, Martin
2004-01-01
For a detailed understanding of biological tissues and proteins and their dynamical processes the 3D structures of the components involved must be known. Most of the structural data have been obtained through the combination of three major techniques: X-ray crystallography, NMR and TEM. These three methods enable the determination of the structure of biological macromolecules at near atomic resolution and each of those was developed over many years to perfection. Nevertheless each one has its...
The role of the wave function in the GRW matter density theory
Energy Technology Data Exchange (ETDEWEB)
Egg, Matthias [University of Lausanne (Switzerland)
2014-07-01
Every approach to quantum mechanics postulating some kind of primitive ontology (e.g., Bohmian particles, a mass density field or flash-like collapse events) faces the challenge of clarifying the ontological status of the wave function. More precisely, one needs to spell out in what sense the wave function ''governs'' the behaviour of the primitive ontology, such that the empirical predictions of standard quantum mechanics are recovered. For Bohmian mechanics, this challenge has been addressed in recent papers by Belot and Esfeld et al. In my talk, I do the same for the matter density version of the Ghirardi-Rimini-Weber theory (GRWm). Doing so will highlight relevant similarities and differences between Bohmian mechanics and GRWm. The differences are a crucial element in the evaluation of the relative strengths and weaknesses of the two approaches, while the similarities can shed light on general characteristics of the primitive ontology approach, as opposed to other interpretative approaches to quantum mechanics.
Dipolar matter-wave solitons in two-dimensional anisotropic discrete lattices
Chen, Huaiyu; Liu, Yan; Zhang, Qiang; Shi, Yuhan; Pang, Wei; Li, Yongyao
2016-05-01
We numerically demonstrate two-dimensional (2D) matter-wave solitons in the disk-shaped dipolar Bose-Einstein condensates (BECs) trapped in strongly anisotropic optical lattices (OLs) in a disk's plane. The considered OLs are square lattices which can be formed by interfering two pairs of plane waves with different intensities. The hopping rates of the condensates between two adjacent lattices in the orthogonal directions are different, which gives rise to a linearly anisotropic system. We find that when the polarized orientation of the dipoles is parallel to disk's plane with the same direction, the combined effects of the linearly anisotropy and the nonlocal nonlinear anisotropy strongly influence the formations, as well as the dynamics of the lattice solitons. Particularly, the isotropy-pattern solitons (IPSs) are found when these combined effects reach a balance. Motion, collision, and rotation of the IPSs are also studied in detail by means of systematic simulations. We further find that these IPSs can move freely in the 2D anisotropic discrete system, hence giving rise to an anisotropic effective mass. Four types of collisions between the IPSs are identified. By rotating an external magnetic field up to a critical angular velocity, the IPSs can still remain localized and play as a breather. Finally, the influences from the combined effects between the linear and the nonlocal nonlinear anisotropy with consideration of the contact and/or local nonlinearity are discussed too.
The role of the wave function in the GRW matter density theory
International Nuclear Information System (INIS)
Every approach to quantum mechanics postulating some kind of primitive ontology (e.g., Bohmian particles, a mass density field or flash-like collapse events) faces the challenge of clarifying the ontological status of the wave function. More precisely, one needs to spell out in what sense the wave function ''governs'' the behaviour of the primitive ontology, such that the empirical predictions of standard quantum mechanics are recovered. For Bohmian mechanics, this challenge has been addressed in recent papers by Belot and Esfeld et al. In my talk, I do the same for the matter density version of the Ghirardi-Rimini-Weber theory (GRWm). Doing so will highlight relevant similarities and differences between Bohmian mechanics and GRWm. The differences are a crucial element in the evaluation of the relative strengths and weaknesses of the two approaches, while the similarities can shed light on general characteristics of the primitive ontology approach, as opposed to other interpretative approaches to quantum mechanics.
Acoustic omni meta-atom for top-down, decoupled access to all octants of a wave parameter space
Koo, Sukmo; Jeong, Jun-ho; Park, Namkyoo
2016-01-01
The common behavior of a wave is determined by wave parameters of its medium, which are generally associated with the characteristic oscillations of its corresponding elementary particles. In the context of metamaterials, the decoupled excitation of these fundamental oscillations would provide an ideal platform for top-down and reconfigurable access to the entire space of constitutive wave parameters; however, this has remained as a conceivable problem that must be accomplished, after being pointed out by Pendry. Here, by focusing on acoustic metamaterials, we achieve the decoupling of density $\\rho$ , modulus B$^{-1}$, and bianisotropy {\\xi} near the Dirac point, by separating the paths of particle momentum to conform to the characteristic oscillations of each macroscopic wave parameter. Independent access to all octants of wave parameter space ($\\rho$ , B$^{-1}$, $\\xi$) = (+/-,+/-,+/-) is thus realized using a single platform that we call an omni meta-atom; as a building block that achieves top-down access ...
International Nuclear Information System (INIS)
A general theorem for matter-wave interferometry that relies only on the unitary property of the Schroedinger equation and not upon any classical or semi-classical approximation restricts the benefits of using long drift spaces. In particular, it negates some, but not all, suggestions that have been made for measuring the neutron's electric-dipole moment by interferometry
Three-Photon Resonant Six-Wave Mixing with Phase-Conjugation Geometry in Na Atomic Vapour
Institute of Scientific and Technical Information of China (English)
ZUO Zhan-Chun; SUN Jiang; MI Xin; YU Zu-He; JIANG Qian; WU Ling-An; FU Pan-Ming
2005-01-01
@@ We report a three-photon resonant six-wave mixing (SWM) with phase- conjugation geometry. It has advantages that phase matching condition is not critical and the generation of SWM signal is efficient. This technique provides a new spectroscopic tool for studying the highly excited atomic or molecular states with high resolution.The feasibility of this technique is demonstrated in sodium vapour.
Schmid, Manfred; Kroupa, Pavel
2014-08-01
We construct an idealised universe for didactic purposes. This universe is assumed to consist of absolute Euclidean space and to be filled with a classical medium which allows for sound waves. A known solution to the wave equation describing the dynamics of the medium is a standing spherical wave. Although this is a problem of classical mechanics, we demonstrate that the Lorentz transformation is required to generate a moving solution from the stationary one. Both solutions are here collectively referred to as "spherons". These spherons exhibit properties which have analogues in the physical description of matter with rest mass, among them de Broglie like phase waves and at the same time "relativistic" effects such as contraction and a speed limit. This leads to a theory of special relativity by assuming the point of view of an observer made of such spheronic "matter". The argument made here may thus be useful as a visualisation or didactic approach to the real universe, in which matter has wave-like properties and obeys the laws of special relativity.
Schmid, Manfred
2014-01-01
We construct an idealized universe for didactic purposes. This universe is assumed to consist of absolute Euclidean space and to be filled with a classical medium which allows for sound waves. A known solution to the wave equation describing the dynamics of the medium is a standing spherical wave. Although this is a problem of classical mechanics, we demonstrate that the Lorentz transformation is required to generate a moving solution from the stationary one. Both solutions are here collectively referred to as "spherons". These spherons exhibit properties which have analogues in the physical description of matter with rest mass, among them de Broglie like phase waves and at the same time "relativistic" effects such as contraction and a speed limit. This leads to a theory of special relativity by assuming the point of view of an observer made of such spheronic "matter". The argument made here may thus be useful as a visualisation or didactic approach to the real universe, in which matter has wave-like properti...
Bastos, Catarina
2016-01-01
In flat spacetime, quantum fluctuations in dark matter, as described as a Bose-Einstein condensate, are stable and display a relativistic Bogoliubov dispersion relation. In the weak gravitational field limit, both relativistic and nonrelativistic models self-gravitating dark matter suggest the formation of structures as the result of a dynamical (Jeans) instability. Here, we show that in the presence of spontaneous symmetry breaking of the dark matter field, the gravitational wave is damped for wave-lengths larger than the Jeans length. Such energy is converted to the Bogoliubov modes of the BEC that in their turn become unstable and grow, leading to the formation of structures even in the absence of expansion. Remarkably, this compensated attenuation/amplification mechanism is the signature of a discrete PT-symmetry-breaking of the system.
Clark, Aurora E.; Sonnenberg, Jason L.; Hay, P. Jeffrey; Martin, Richard L.
2004-08-01
Recent advances in computational methods have made it possible to calculate the wave functions for a wide variety of simple actinide complexes. Equally important is the ability to analyze the information contained therein and produce a chemically meaningful understanding of the electronic structure. Yet the performance of the most common wave function analyses for the calculation of atomic charge and bond order has not been thoroughly investigated for actinide systems. This is particularly relevant because the calculation of charge and bond order even in transition metal complexes is known to be fraught with difficulty. Here we use Mulliken, Löwdin, natural population analysis, atoms-in-molecules (AIM), and fuzzy atom techniques to determine the charges and bond orders of UO22+, PuO22+, UO2, UO2Cl42-, UO2(CO)52+, UO2(CO)42+, UO2(CN)53-, UO2(CN)42-, UO2(OH)53-, and UO2(OH)42-. This series exhibits a clear experimental and computational trend in bond lengths and vibrational frequencies. The results indicate that Mulliken and Löwdin populations and bond orders are unreliable for the actinyls. Natural population analysis performs well after modification of the partitioning of atomic orbitals to include the 6d in the valence space. The AIM topological partitioning is insensitive to the electron donating ability of the equatorial ligands and the relative atomic volume of the formally U(VI) center is counterintuitively larger than that of O2- in the UO22+ core. Lastly, the calibrated fuzzy atom method yields reasonable bond orders for the actinyls at significantly reduced computational cost relative to the AIM analysis.
Slatyer, Tracy R.
2016-01-01
Recent measurements of the cosmic microwave background (CMB) anisotropies by Planck provide a sensitive probe of dark matter annihilation during the cosmic dark ages, and specifically constrain the annihilation parameter feff⟨σ v ⟩/mχ. Using new results (paper II) for the ionization produced by particles injected at arbitrary energies, we calculate and provide feff values for photons and e+e- pairs injected at keV-TeV energies; the feff value for any dark matter model can be obtained straightforwardly by weighting these results by the spectrum of annihilation products. This result allows the sensitive and robust constraints on dark matter annihilation presented by the Planck collaboration to be applied to arbitrary dark matter models with s -wave annihilation. We demonstrate the validity of this approach using principal component analysis. As an example, we integrate over the spectrum of annihilation products for a range of Standard Model final states to determine the CMB bounds on these models as a function of dark matter mass, and demonstrate that the new limits generically exclude models proposed to explain the observed high-energy rise in the cosmic ray positron fraction. We make our results publicly available at http://nebel.rc.fas.harvard.edu/epsilon.
Inertial quantum sensors using light and matter
Barrett, B; Bouyer, P
2016-01-01
The past few decades have seen dramatic progress in our ability to manipulate and coherently control matter-waves. Although the duality between particles and waves has been well tested since de Broglie introduced the matter-wave analog of the optical wavelength in 1924, manipulating atoms with a level of coherence that enables one to use these properties for precision measurements has only become possible with our ability to produce atomic samples exhibiting temperatures of only a few millionths of a degree above absolute zero. Since the initial experiments a few decades ago, the field of atom optics has developed in many ways, with both fundamental and applied significance. The exquisite control of matter waves offers the prospect of a new generation of force sensors exhibiting unprecedented sensitivity and accuracy, for applications from navigation and geophysics to tests of general relativity. Thanks to the latest developments in this field, the first commercial products using this quantum technology are n...
Gao, W; Cheng, H; Zhang, S S; Liu, H P
2015-01-01
We have investigated the wave-function feature of Rydberg sodium in a uniform electric field and found that the core-induced interaction of non-hydrogenic atom in electric field can be directly visualized in the wave-function. As is well known, the hydrogen atom in electric field can be separated in parabolic coordinates (\\eta, \\xi), whose eigen-function can show a clear pattern towards negative and positive directions corresponding to the so-called red and blue states without ambiguity, respectively. It can be served as a complete orthogonal basis set to study the core-induced interaction of non-hydrogenic atom in electric field. Owing to complete different patterns of the probability distribution for red and blue states, the interaction can be visualized in the wave-function directly via superposition. Moreover, the constructive and destructive interferences between red and blue states are also observed in the wave-function, explicitly explaining the experimental measurement for the spectral oscillator stre...
Optical resonator for a standing wave dipole trap for fermionic lithium atoms
International Nuclear Information System (INIS)
This thesis reports on the the construction of an optical resonator for a new resonator dipole trap to store the fermionic 6Li-isotope and to investigate its scattering properties. It was demonstrated that the resonator enhances the energy density of a (1064 nm and 40 mW) laser beam by a factor of more than 100. A fused silica vacuum cell is positioned inside the resonator under Brewster's angle. The losses of the resonator depend mainly on the optical quality of the cell. The expected trap depth of the dipole trap is 200 μK and the photon scattering rate is expected to be about 0.4 s-1. The resonator is stabilized by means of a polarization spectroscopy method. Due to high trap frequencies, which are produced by the tight enclosure of the standing wave in the resonator, the axial motion must be quantized. A simple model to describe this quantization has been developed. A magneto-optical trap, which serves as a source of cold lithium atoms, was put in operation. (orig.)
Karlovets, D V; Serbo, V G
2015-01-01
Laser photons carrying non-zero orbital angular momentum are known and exploited during the last twenty years. Recently it has been demonstrated experimentally that such (twisted) electrons can be produced and even focused to a subnanometer scale. Thus, twisted electrons emerge as a new tool in atomic physics. The state of a twisted electron can be considered as a specific wave packet of plane waves. In the present paper-I we consider elastic scattering of the wave packets of fast non-relativistic particles on a potential field. We obtain simple and convenient formulae for a number of events in such a scattering. The equations derived represent, in fact, generalization of the well-known Born approximation for the case when finite sizes and inhomogeneity of the initial packet should be taken into account. To illustrate the obtained results, we consider two simple models corresponding to scattering of a Gaussian wave packet on the Gaussian potential and on the hydrogen atom. The scattering of twisted electrons ...
Cho, Hideo; Oka, Daichi; Matsuo, Takuma
In this study we attempted to evaluate the degree of degradation of an unsaturated polyester resin when it was degraded by exposing it to hot water at 90°C, using the frequency of zero-group-velocity (ZGV) Lamb waves. The energy of ZGV Lamb waves does not propagate while the phase velocity remains finite. We generated ZGV Lamb waves with a Q-switched YAG laser and detected them with a focused air-coupled transducer at the same area of an irradiation point of the YAG laser in con-contact matter. A change in measured frequencies of ZGV Lamb waves decreased with increase of exposed period to hot water and are corresponding to the change in Young's modulus and thickness of the plate near the exposed surface
Kengne, E.; Lakhssassi, A.
2015-03-01
We consider a lossless one-dimensional nonlinear discrete bi-inductance electrical transmission line made of N identical unit cells. When lattice effects are considered, we use the reductive perturbation method in the semidiscrete limit to show that the dynamics of modulated waves can be modeled by the classical nonlinear Schrödinger (CNLS) equation, which describes the modulational instability and the propagation of bright and dark solitons on a continuous-wave background. Our theoretical analysis based on the CNLS equation predicts either two or four frequency regions with different behavior concerning the modulational instability of a plane wave. With the help of the analytical solutions of the CNLS equation, we investigate analytically the effects of the linear capacitance CS on the dynamics of matter-wave solitons in the network. Our results reveal that the linear parameter CS can be used to manipulate the motion of bright, dark, and kink soliton in the network.
Constraining warm dark matter mass with cosmic reionization and gravitational wave
Tan, W W; Cheng, K S
2016-01-01
We constrain the warm dark matter (WDM) particle mass with the observations of cosmic reionization and CMB optical depth. We suggest that the GWs from stellar mass black holes (BHs) could give a further constraint on WDM particle mass for future observations. The star formation rates (SFRs) of Population I/II (Pop I/II) and Population III (Pop III) stars are also derived. If the metallicity of the universe have been enriched beyond the critical value of $Z_{\\rm crit}=10^{-3.5}Z_{\\odot}$, the star formation shift from Pop III to Pop I/II stars. Our results show that the SFRs are quite dependent on the WDM particle mass, especially at high redshifts. Combing with the reionization history and CMB optical depth derived from the recent \\emph{Planck} mission, we find that the current data requires the WDM particle mass in a narrow range of $1 < m_x < 3$ keV. Furthermore, we suggest that the stochastic gravitational wave background (SGWB) produced by stellar BHs could give a further constraint on the WDM parti...
Gravitational waves as a probe of dark matter mini-spikes
Eda, Kazunari; Kuroyanagi, Sachiko; Silk, Joseph
2014-01-01
Recent studies show that an intermediate mass black hole (IMBH) may develop a dark matter (DM) mini-halo according to some BH formation scenarios. We consider a binary system composed of an IMBH surrounded by a DM mini-spike and a stellar mass object orbiting around the IMBH. The binary evolves due to gravitational pull and dynamical friction from the DM mini-spike and back-reaction from its gravitational wave (GW) radiation which can be detected by future space-borne GW experiments such as eLISA/NGO. We consider a single power-law model for the DM mini-spike which is assumed to consist of non-annihilating DM particles and demonstrate that an eLISA/NGO detection of GW from such a binary enables us to measure the DM mini-spike parameters very accurately. For instance, in our reference case originally advocated by Zhao and Silk (2005) and Bertone et al. (2005), we could determine the power-law index $\\alpha$ of the DM mini-spike radial profile with a 1 $\\sigma$ relative error of $\\pm 5\\times 10^{-6}$ for a GW s...
International Nuclear Information System (INIS)
We investigate the linear response of a nonrelativistic hydrogenlike atom to a harmonic uniform electric field, which is switched on adiabatically. For the electron initially in an arbitrary bound chemical bondnlm> state, the first-order correction to the wave function has been written in terms of a vector function w/sub n//sub l//sub m/. We report an exact closed-form expression of the vector w/sub n//sub l//sub m/ that we have derived using the Coulomb Green's function. Our general analytic results prove to be useful in a systematic study of two-photon processes involving the hydrogen atom
Dual-dressed four-wave mixing and dressed six-wave mixing in a five-level atomic system
Institute of Scientific and Technical Information of China (English)
Cuicui Zuo; Yigang Du; Tong Jiang; Zhiqiang Nie; Yanpeng Zhang; Huaibin Zheng; Chenli Gan; Weifeng Zhang; Keqing Lu
2008-01-01
We study the co-existing four-wave mixing (FWM) process with two dressing fields and the six-wave mixing (SWM) process with one dressing field in a five-level system with carefully arranged laser beams. We also show two kinds of doubly dressing mechanisms in the FWM process. FWM and SWM signals propagatingalong the same direction compete with each other. With the properly controlled dressing fields, the FWM signals can be suppressed, while the SWM signals have been enhanced.
Kozlowski, Wojciech; Mekhov, Igor B
2014-01-01
We show that light scattering from an ultracold gas reveals not only density correlations, but also matter-field interference at its shortest possible distance in an optical lattice, which defines key properties such as tunneling and matter-field phase gradients. This signal can be enhanced by concentrating probe light between lattice sites rather than at density maxima. As addressing between two single sites is challenging, we focus on global nondestructive scattering, allowing probing order parameters, matter-field quadratures and their squeezing. The scattering angular distribution displays peaks even if classical diffraction is forbidden and we derive generalized Bragg conditions. Light scattering distinguishes all phases in the Mott insulator - superfluid - Bose glass phase transition.
International Nuclear Information System (INIS)
An extended variation approach to describing the dynamic evolution of self-attractive Bose—Einstein condensates is developed. We consider bright matter-wave solitons in the presence of a parabolic magnetic potential and a time-space periodic optical lattice. The dynamics of condensates is shown to be well approximated by four coupled nonlinear differential equations. A noteworthy feature is that the extended variation approach gives a critical strength ratio to support multiple stable lattice sites for the condensate. We further examine the existence of the solitons and their stabilities at the multiple stable lattice sites. In this case, the analytical predictions of Bose—Einstein condensates variational dynamics are found to be in good agreement with numerical simulations. We then find a stable region for successful manipulating matter-wave solitons without collapse, which are dragged from an initial stationary to a prescribed position by a moving periodic optical lattice. (general)
International Nuclear Information System (INIS)
By two direct assumption methods and symbolic computation, we present two families of one-soliton solutions and a family of two-soliton solutions with some arbitrary functions for the three-dimensional Gross—Pitaevskii equation with time-space modulation. Then we investigate the dynamics of these matter-wave solitons in three-dimensional Bose—Einstein condensates. We can see that the intensities of both one-solitons and two-solitons first increase rapidly to the condensation peak value, then decay very slowly to the background value. Thus these matter-wave solitons in three-dimensional Bose—Einstein condensates can remain for a sufficiently long time to be fully observed and modulated for real applications in today's experiments
Slatyer, Tracy R
2015-01-01
Recent measurements of the cosmic microwave background (CMB) anisotropies by Planck provide a sensitive probe of dark matter annihilation during the cosmic dark ages, and specifically constrain the annihilation parameter $f_\\mathrm{eff} \\langle \\sigma v \\rangle/m_\\chi$. Using new results (Paper II) for the ionization produced by particles injected at arbitrary energies, we calculate and provide $f_\\mathrm{eff}$ values for photons and $e^+e^-$ pairs injected at keV-TeV energies; the $f_\\mathrm{eff}$ value for any dark matter model can be obtained straightforwardly by weighting these results by the spectrum of annihilation products. This result allows the sensitive and robust constraints on dark matter annihilation presented by the Planck Collaboration to be applied to arbitrary dark matter models with $s$-wave annihilation. We demonstrate the validity of this approach using principal component analysis. As an example, we integrate over the spectrum of annihilation products for a range of Standard Model final s...
Cooperative scattering of light and atoms in ultracold atomic gases
Uys, H.; Meystre, P.
2008-07-01
Superradiance and coherent atomic recoil lasing are two closely related phenomena, both resulting from the cooperative scattering of light by atoms. In ultracold atomic gases below the critical temperature for Bose-Einstein condensation these processes take place with the simultaneous amplification of the atomic matter waves. We explore these phenomena by surveying some of the experimental and theoretical developments that have emerged in this field of study since the first observation of superradiant scattering from a Bose-Einstein condensate in 1999 [1].
Cooperative scattering of light and atoms in ultracold atomic gases
International Nuclear Information System (INIS)
Superradiance and coherent atomic recoil lasing are two closely related phenomena, both resulting from the cooperative scattering of light by atoms. In ultracold atomic gases below the critical temperature for Bose-Einstein condensation these processes take place with the simultaneous amplification of the atomic matter waves. We explore these phenomena by surveying some of the experimental and theoretical developments that have emerged in this field of study since the first observation of superradiant scattering from a Bose-Einstein condensate in 1999 [1
International Nuclear Information System (INIS)
The hyperspherical partial wave approach has been applied here in the study of double photoionization of the helium atom for equal-energy-sharing geometries at 20 eV excess energy. Calculations have been done both in length and velocity gauges and are found to agree with each other, with the CCC results and with experiments and to exhibit some advantages for the corresponding three-particle wavefunction over other wavefunctions in use
Loth, Sebastian
2008-01-01
This volume reports measurements of single dopant atoms in III-V semiconductors with low temperature scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). It studies the anisotropic spatial distribution of acceptor induced tunneling processes at the {110} cleavage planes. Two different tunneling processes are identified: conventional imaging of the squared acceptor wave function and resonant tunneling at the charged acceptor. A thorough analysis of the tip induced spa...
Atom gravimeters and gravitational redshift
Wolf, Peter; Borde, Christian J; Reynaud, Serge; Salomon, Christophe; Cohen-Tannoudji, Claude; 10.1038/nature09340
2010-01-01
In a recent paper, H. Mueller, A. Peters and S. Chu [A precision measurement of the gravitational redshift by the interference of matter waves, Nature 463, 926-929 (2010)] argued that atom interferometry experiments published a decade ago did in fact measure the gravitational redshift on the quantum clock operating at the very high Compton frequency associated with the rest mass of the Caesium atom. In the present Communication we show that this interpretation is incorrect.
Lush, David C
2016-01-01
It is investigated whether the Planck-Einstein relation between the energy and frequency of light quanta, and the de Broglie wavelength of matter can be wholly or partially explained as consequences of the relativistic Doppler shift of electromagnetic fields caused by oscillating electric dipoles within the elementary particles constituting light and matter, and their electromagnetic interaction with similarly constituted particles. Assuming the oscillation is at the zitterbewegung frequency of the Dirac electron theory, the photon energy is found to be approximately half the value expected according to the Planck-Einstein relation. The relativistically Doppler shifted time-symmetric electromagnetic field due to the particle is found to have a superluminal phase velocity equal to that of the de Broglie matter wave, a group velocity equal to the particle velocity, and a wavelength of \\(h/p\\).
Four-wave mixing and six-wave mixing in a four-level confined atomic system
International Nuclear Information System (INIS)
We have investigated coexisting four-wave mixing and six-wave mixing (SWM) in ultra-thin, micrometre and long vapour cells. There exists competition between Dicke-narrowing features and polarization interference in the micrometre cell. The oscillation behaviour of SWM signal intensities and linewidths results from destructive interference. With a larger destructive interference, the SWM signal in ultra-thin cells shows a narrow spectrum, in contrast to the long cell case. Due to the Dicke-narrowing features, a narrow spectrum can be obtained, and such spectra can be used for high precision measurements and metrological standards. (classical areas of phenomenology)
Chen, Jiunn-Wei; Lin, Shin-Ted; Liu, C -P; Singh, Lakhwinder; Wong, Henry T; Wu, Chih-Liang; Wu, Chih-Pan
2016-01-01
The transition magnetic moment of a sterile-to-active neutrino conversion gives rise to not only radiative decay of a sterile neutrino, but also its non-standard interaction (NSI) with matter. For sterile neutrinos of keV-mass as dark matter candidates, their decay signals are actively searched for in cosmic X-ray spectra. In this work, we consider the NSI that leads to atomic ionization, which can be detected by direct dark matter experiments. It is found that this inelastic scattering process for a nonrelativistic sterile neutrino has a pronounced enhancement in the differential cross section at energy transfer about half of its mass, manifesting experimentally as peaks in the measurable energy spectra. The enhancement effects gradually smear out as the sterile neutrino becomes relativistic. Using data taken with germanium detectors that have fine energy resolution in keV and sub-keV regimes, constraints on sterile neutrino mass and its transition magnetic moment are derived and compared with those from ast...
DEFF Research Database (Denmark)
Johnsen, Kristinn; Yngvason, Jakob
1996-01-01
We report on a numerical study of the density matrix functional introduced by Lieb, Solovej, and Yngvason for the investigation of heavy atoms in high magnetic fields. This functional describes exactly the quantum mechanical ground state of atoms and ions in the limit when the nuclear charge Z and...... obtained by other methods. For iron at B=1012 G the ground-state energy differs by less than 2% from the Hartree-Fock value. We have also studied the maximal negative ionization of heavy atoms in this model at various field strengths. In contrast to Thomas-Fermi type theories atoms can bind excess negative...... the electron number N tend to infinity with N/Z fixed, and the magnetic field B tends to infinity in such a way that B/Z4/3→∞. We have calculated electronic density profiles and ground-state energies for values of the parameters that prevail on neutron star surfaces and compared them with results...
Three-dimensional solitons in coupled atomic-molecular Bose-Einstein condensates
Vaughan, T. G.; Kheruntsyan, K. V.; Drummond, P. D.
2004-01-01
We present a theoretical analysis of three-dimensional (3D) matter-wave solitons and their stability properties in coupled atomic and molecular Bose-Einstein condensates (BEC). The soliton solutions to the mean-field equations are obtained in an approximate analytical form by means of a variational approach. We investigate soliton stability within the parameter space described by the atom-molecule conversion coupling, atom-atom s-wave scattering, and the bare formation energy of the molecular...
Rabi Spectroscopy and Excitation in a Gravity Cavity of Neutron Matter Waves
International Nuclear Information System (INIS)
Full text: Gravity experiments might provide an answer for the 'big questions' about space, time, and a unification of all forces, where - as most physicists believe - space-time is not restricted to four dimensions. Hypothetical extra-dimensions, curled up to cylinders or tori with a small compactification radius should lead to deviations from Newton's gravitational law at very small distances. These ideas triggered gravity experiments of different kinds, which in the past ten years have validated Newton's gravitational law down to about 50 μm. The basic problem in searching for new physics at small distances is that the size of the objects under study must be reduced, too, going along with a reduction of signal intensity. At the same time, the electrostatic background increases. Our way out is the interaction of a macroscopic system, here a mirror for neutron reflection, with a pure quantum mechanical system, i.e. the excitation of bound quantum states of a neutron in the gravity potential of the earth. We demonstrate that the method of Rabi spectroscopy usually used in atom optics can now be applied to quantum states in the gravity potential of the earth together with a mechanical or magnetic coupling. This technique allows a precise measurement of quantum mechanical phase shifts of a Schroedinger wave packet bouncing off a hard surface in the gravitational field of the earth. The idea behind this method is that phase shifts in gravity potentials can be related to frequency measurements with unprecedented accuracy. These spectroscopy experiments on gravitation within the Bounce measurements are a starting point for experiments linked to string theories with large volume compactifications and/or cosmology because Newtonian gravity and hypothetical fifth forces evolve with different phase information and limits on a hypothetical strength can be derived. (author)
Dressed multi-wave mixing in a Ⅴ-type four-level atomic system
Institute of Scientific and Technical Information of China (English)
2007-01-01
The dressed four- and six-wave mixings in a Ⅴ-type four-level system are considered. Under two different dressed conditions, two- and three-photon resonant Autler-Townes splittings, accompanied by enhancement and suppression of wave mixing signal, are obtained analytically. Meanwhile, an electromagnetic induced transparency of multi-wave mixing is presented, which shows multiple peaks and asymmetric effects caused by one-photon, two-photon and three-photon resonances, separately. The slow light propagation multiple region of multi-wave mixing signal is also obtained.
Salvat, Francesc; Jablonski, Aleksander; Powell, Cedric J.
2005-01-01
The FORTRAN 77 code system ELSEPA for the calculation of elastic scattering of electrons and positrons by atoms, positive ions and molecules is presented. These codes perform relativistic (Dirac) partial-wave calculations for scattering by a local central interaction potential V(r). For atoms and ions, the static-field approximation is adopted, with the potential set equal to the electrostatic interaction energy between the projectile and the target, plus an approximate local exchange interaction when the projectile is an electron. For projectiles with kinetic energies up to 10 keV, the potential may optionally include a semiempirical correlation-polarization potential to describe the effect of the target charge polarizability. Also, for projectiles with energies less than 1 MeV, an imaginary absorptive potential can be introduced to account for the depletion of the projectile wave function caused by open inelastic channels. Molecular cross sections are calculated by means of a single-scattering independent-atom approximation in which the electron density of a bound atom is approximated by that of the free neutral atom. Elastic scattering by individual atoms in solids is described by means of a muffin-tin model potential. Partial-wave calculations are feasible on modest personal computers for energies up to about 5 MeV. The ELSEPA code also implements approximate factorization methods that allow the fast calculation of elastic cross sections for much higher energies. The interaction model adopted in the calculations is defined by the user by combining the different options offered by the code. The nuclear charge distribution can be selected among four analytical models (point nucleus, uniformly charged sphere, Fermi's distribution and Helm's uniform-uniform distribution). The atomic electron density is handled in numerical form. The distribution package includes data files with electronic densities of neutral atoms of the elements hydrogen to lawrencium ( Z=1
Studenikin, Alexander
2008-01-01
We present quite a powerful method in investigations of different phenomena that can appear when neutrinos and electrons propagate in background matter. This method implies use of exact solutions of modified Dirac equations that contain the correspondent effective potentials accounting for the matter influence on particles. For several particular cases the exact solutions of modified Dirac and Dirac-Pauli equations for a neutrino and an electron in the background environment of different composition are obtained (the case of magnetized matter is also considered). Neutrino reflection, trapping, neutrino pair creation and annihilation in matter and neutrino energy quantization in a rotating medium are discussed. The neutrino Green functions in matter are also derived. The two recently proposed mechanisms of electromagnetic radiation by a neutrino and an electron in matter (the spin light of neutrino and electron, $SL\
Eda, Kazunari; Itoh, Yousuke; Kuroyanagi, Sachiko; Silk, Joseph
2013-05-31
An intermediate-mass black hole (IMBH) may have a dark-matter (DM) minihalo around it and develop a spiky structure within less than a parsec from the IMBH. When a stellar mass object is captured by the minihalo, it eventually infalls into such an IMBH due to gravitational wave backreaction which in turn could be observed directly by future space-borne gravitational wave experiments such as eLISA and NGO. In this Letter, we show that the gravitational wave (GW) detectability strongly depends on the radial profile of the DM distribution. So if the GW is detected, the power index, that is, the DM density distribution, would be determined very accurately. The DM density distribution obtained would make it clear how the IMBH has evolved from a seed black hole and whether the IMBH has experienced major mergers in the past. Unlike the γ-ray observations of DM annihilation, GW is just sensitive to the radial profile of the DM distribution and even to noninteracting DM. Hence, the effect we demonstrate here can be used as a new and powerful probe into DM properties. PMID:23767709
Inertial quantum sensors using light and matter
Barrett, B.; Bertoldi, A.; Bouyer, P.
2016-05-01
The past few decades have seen dramatic progress in our ability to manipulate and coherently control matter-waves. Although the duality between particles and waves has been well tested since de Broglie introduced the matter-wave analog of the optical wavelength in 1924, manipulating atoms with a level of coherence that enables one to use these properties for precision measurements has only become possible with our ability to produce atomic samples exhibiting temperatures of only a few millionths of a degree above absolute zero. Since the initial experiments a few decades ago, the field of atom optics has developed in many ways, with both fundamental and applied significance. The exquisite control of matter waves offers the prospect of a new generation of force sensors exhibiting unprecedented sensitivity and accuracy, for applications from navigation and geophysics to tests of general relativity. Thanks to the latest developments in this field, the first commercial products using this quantum technology are now available. In the future, our ability to create large coherent ensembles of atoms will allow us an even more precise control of the matter-wave and the ability to create highly entangled states for non-classical atom interferometry.
Condensed matter physics - From cold atoms to high critical temperature superconductors
International Nuclear Information System (INIS)
This book is a reference in condensed matter physics and proposes a review of current issues in this field such as strongly correlated particle systems, physics beyond Fermi liquid, non conventional superconductivity. More precisely, it addresses, presents or discusses the one- and two-dimensional Ising model, generalities on phase transitions, medium field approximations, critical phenomena, Kosterlitz-Thouless transitions, free electron gas, the Landau theory of Fermi liquids, physics beyond Fermi liquid, localized magnetism, itinerant electron magnetism, conventional superconductivity, non conventional superconductors, and examples of analogies developed by Pierre-Gilles de Gennes
Soliton Atom Laser with Quantum State Transfer Property
Institute of Scientific and Technical Information of China (English)
LIU Xiong-Jun; JING Hui; GE Mo-Lin
2006-01-01
@@ We study the nonlinear effects in the quantum states transfer technique from photons to matter waves in the three-level case, which may provide the formation of a soliton atom laser with nonclassical atoms. The validity of quantum transfer mechanism is confirmed in the presence of the intrinsic nonlinear atomic interactions. The accompanied frequency chirp effect is shown to have no influence on the grey solitons formed by the output atom laser and the possible quantum depletion effect is also briefly discussed.
Chameleon induced atomic afterglow
Energy Technology Data Exchange (ETDEWEB)
Brax, Philippe [CEA, IPhT, CNRS, Gif-sur-Yvette (France). Inst. de Physique Theorique; Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2010-09-15
The chameleon is a scalar field whose mass depends on the density of its environment. Chameleons are necessarily coupled to matter particles and will excite transitions between atomic energy levels in an analogous manner to photons. When created inside an optical cavity by passing a laser beam through a constant magnetic field, chameleons are trapped between the cavity walls and form a standing wave. This effect will lead to an afterglow phenomenon even when the laser beam and the magnetic field have been turned off, and could be used to probe the interactions of the chameleon field with matter. (orig.)
Atomic origin of the scanning tunneling microscopy images of charge-density-waves on 1T-TaSe{sub 2}
Energy Technology Data Exchange (ETDEWEB)
Stoltz, D. [Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden (Netherlands)], E-mail: stoltz@physics.leidenuniv.nl; Bielmann, M.; Schlapbach, L. [Swiss Federal Lab for Materials Science and Technology (EMPA), CH-8600 Duebendorf (Switzerland); Bovet, M. [Institut de Physique, Universite de Neuchatel, CH-2000 Neuchatel (Switzerland); Berger, H. [Institut de Physique Appliquee, EPF, 1015 Lausanne (Switzerland); Goethelid, M. [Materialfysik, MAP, KTH-Electrum, SE-16440 Kista (Sweden); Stoltz, S.E. [MAX-Lab, Lund University, SE-22100 Lund (Sweden); Starnberg, H.I. [Department of Physics, Goeteborg University and Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)
2008-07-01
We show atomically resolved scanning tunneling microscopy (STM) images of charge density waves (CDWs) at room temperature together with angle-resolved photoelectron band-mapping of 1T-TaSe{sub 2}. By comparing the results of these two techniques, we demonstrate the atomic structure of the CDW-features observed by the STM and atomic origin of the reconstructed band-structure in this material.
A coupled microwave-cavity system in the Rydberg-atom cavity detector for dark matter axions
Tada, M; Shibata, M; Kominato, K; Ogawa, I; Funahashi, H; Yamamoto, K; Matsuki, S
2001-01-01
A coupled microwave-cavity system of cylindrical TM$_{010}$ single-mode has been developed to search for dark matter axions around 10 $\\mu {\\rm eV}$(2.4 GHz) with the Rydberg-atom cavity detector at 10 mK range temperature. One component of the coupled cavity (conversion cavity) made of oxygen-free high-conductivity copper is used to convert an axion into a single photon with the Primakoff process in the strong magnetic field, while the other component (detection cavity) made of Nb is utilized to detect the converted photons with Rydberg atoms passed through it without magnetic field. Top of the detection cavity is attached to the bottom flange of the mixing chamber of a dilution refrigerator, thus the whole cavity is cooled down to 10 mK range to reduce the background thermal blackbody-photons in the cavity. The cavity resonant frequency is tunable over $\\sim$ 15% by moving dielectric rods inserted independently into each part of the cavities along the cylindrical axis. In order to reduce the heat load from ...
Liu, Junyang; Hang, Chao; Huang, Guoxiang
2016-06-01
We propose a scheme to demonstrate the existence of optical Peregrine rogue waves and Akhmediev and Kuznetsov-Ma breathers and realize their active control via electromagnetically induced transparency (EIT). The system we suggest is a cold, Λ -type three-level atomic gas interacting with a probe and a control laser fields and working under EIT condition. We show that, based on EIT with an incoherent optical pumping, which can be used to cancel optical absorption, (1+1)-dimensional optical Peregrine rogue waves, Akhmediev breathers, and Kuznetsov-Ma breathers can be generated with very low light power. In addition, we demonstrate that the Akhmediev and Kuznetsov-Ma breathers in (2+1)-dimensions obtained can be actively manipulated by using an external magnetic field. As a result, these breathers can display trajectory deflections and bypass obstacles during propagation.
Unlocking the full potential of wave-matter nonlinear coupling in the epsilon-near-zero regime
Ciattoni, Alessandro; Marini, Andrea; Di Falco, Andrea; Faccio, Daniele; Scalora, Michael
2015-01-01
In recent years, unconventional metamaterial properties have triggered a revolution of electromagnetic research which has unveiled novel scenarios of wave-matter interaction. A very small dielectric permittivity is a leading example of such unusual features, since it produces an exotic static-like regime where the electromagnetic field is spatially slowly-varying over a physically large region. The so-called epsilon-near-zero metamaterials thus offer an ideal platform where to manipulate the inner details of the "stretched" field. Here we theoretically prove that a standard nonlinearity is able to operate such a manipulation to the point that even a thin slab produces a dramatic nonlinear pulse transformation, if the dielectric permittivity is very small within the field bandwidth. The predicted non-resonant releasing of full nonlinear coupling produced by the epsilon-near-zero condition does not resort to any field enhancement mechanisms and opens novel routes to exploiting matter nonlinearity for steering t...
International Nuclear Information System (INIS)
Organometallic chemical vapor deposition of silicon nitride films enhanced by atomic nitrogen generated from surface-wave plasma is investigated. Feasibility of precursors of triethylsilane (TES) and bis(dimethylamino)dimethylsilane (BDMADMS) is discussed based on a calculation of bond energies by computer simulation. Refractive indices of 1.81 and 1.71 are obtained for deposited films with TES and BDMADMS, respectively. X-ray photoelectron spectroscopy (XPS) analysis of the deposited film revealed that TES-based film coincides with the stoichiometric thermal silicon nitride
Possibility of significant heating of H atoms in high-density, helicon-wave excited hydrogen plasmas
Sasaki, K.; Nakamoto, M.; Kadota, K.
2001-10-01
In the present work, we measured the distribution of H atom density in high-density hydrogen plasmas excited by helicon-wave discharges. The measurement was carried out in a linear machine with a uniform magnetic field of 1 kG along the cylindrical axis of the vacuum chamber. Plasmas were produced in a glass tube of 3 cm diameter by applying various rf powers to a helical antenna wound around the glass tube. The hydrogen gas pressure was 30--100 mTorr. Since the plasma was confined radially by the external magnetic field, we obtained a slender plasma column of 3 cm diameter at the center of the vacuum chamber. The distribution of the H atom density was measured by (2+1)-photon laser-induced fluorescence spectroscopy. As a result, it was found that the distribution of the H atom density had a deep dip in the high-density operation. The location of the dip corresponded to the high-density plasma column. A possible explanation for the deep dip in the plasma column is significant heating of H atoms. In general, it is known that temperatures of neutral species in low-pressure plasmas are not so far from room temperature. However, the present experimental result suggests the possibility of significant heating of neutral radicals in low-pressure, high-density plasmas. The high temperature may influence the transport and kinetics of reactive species in plasmas.
Large momentum transfer atom interferometry with Coriolis force compensation
Kuan, Pei-Chen; Lan, Shau-Yu; Estey, Brian; Haslinger, Philipp; Mueller, Holger
2012-06-01
Light-pulse atom interferometers use atom-photon interactions to coherently split, guide, and recombine freely falling matter-waves. Because of Earth's rotation, however, the matter-waves do not recombine precisely, which causes severe loss of contrast in large space-time atom interferometers. I will present our recent progress in using a tip-tilt mirror to remove the influence of the Coriolis force from Earth's rotation. Therefore, we improve the contrast and suppress systematic effects, also reach what is to our knowledge the largest spacetime area.
Measuring the weak value of momentum in a double slit atom interferometer
Morley, J.; Edmunds, P. D.; Barker, P. F.
2016-03-01
We describe the development of an experiment to measure the weak value of the transverse momentum operator (local momentum [1]) of cold atoms passing through a matter- wave interferometer. The results will be used to reconstruct the atom's average trajectories. We describe our progress towards this goal using laser cooled argon atoms.
Mass Predictions of Atomic Nuclei in the Infinite Nuclear Matter Model
Nayak, R C
2012-01-01
We present here the mass excesses, binding energies, one- and two- neutron, one and two- proton and \\alpha-particle separation energies of 6727 nuclei in the ranges 4 \\leq Z \\leq 120 and 8 \\leq A \\leq 303 calculated in the infinite nuclear matter model. Compared to our predictions of 1999 mass table, the present ones are obtained using larger data base of 2003 mass table of Wapstra and Audi and resorting to higher accuracy in the solutions of the \\eta-differential equations of the INM model. The local energy \\eta's supposed to carry signature of the characteristic properties of nuclei are found to possess the predictive capability. In fact \\eta-systematics reveal new magic numbers in the drip-line regions giving rise to new islands of stability supported by relativistic mean field theoretic calculations. This is a manifestation of a new phenomenon where shell-effect overcomes the instability due to repulsive components of the nucleon-nucleon force broadening the stability peninsula. The two-neutron separation...
Multiple weak shock waves induced by heavy ion beams in solid matter
Constantin, Carmen
2002-01-01
High energy density in matter is of fundamental interest for various fields of science, including plasma physics, astrophysics, geophysics and applications such as possible future energy sources based on inertial confinement fusion. Intense, relativistic heavy ion beams are ideally suited to produce high energy density in matter. The heavy ion synchrotron SIS-18 at the Gesellschaft fuer Schwerionenforschung (GSI) can supply intense ion beam bunches, of about 5 109 particles for U92+, delivere...
Theory of two-atom coherence in gases. II. Continuous-wave spectra
Ben-Reuven, Abraham
1980-12-01
General expressions are derived for the spectral line shapes of resonance absorption and scattering of coherent radiation in collision-broadened gases, taking into account effects of coherent excitation of two or more atoms (or molecules), as steady-state solutions of a hierarchy of master equations described in a previous publication (paper I). Coupling between the coherent motions of the atoms, provided by a Bethe-Salpeter-type effective interaction, in the binary-collision approximation, forms the essential mechanism for introducing cooperative coherent effects into the steady-state spectra. Explicit expressions are given for the effects of two-atom coherence in the binary-collision approximation, in which the Bloch-type dressed-atom self-energy superoperator is modified by the presence of collisions in which both atoms retain memory of their coherent propagation before the collision. The self-energies include the effects of resonance exchange symmetrization in self-broadening, and are renormalized by the coincidence of radiative transitions during the collisions. The impact (near-resonance) and the quasistatic (line-wing) limits of the applied-frequency detunings are discussed. In the quasistatic limit, coherent many-atom excitations become irrelevant; however, interactions of both collision partners with the radiation during the collision accounts for such phenomena as collision-induced absorption or radiative collisions. In the impact limit, the inclusion of the Bethe-Salpeter interactions allows for the appearance of two-atom resonances. Magnitude estimates of these effects are discussed. Effects of higher-rank (many-body) coherences are formally discussed with the help of a diagrammatic method, leading into implicit bootstrap equations that can be solved by iterative or other procedures.
Hindy, Kamal T.; And Others
1992-01-01
An atmospheric pollution study applies direct current plasma atomic emission spectrometry (DCP-AES) to samples of total suspended particulate matter collected in two industrial areas and one residential area, and cement dust collected near major cement factories. These samples were analyzed for vanadium, tin, and mercury. The results indicate the…
Eda, Kazunari; Kuroyanagi, Sachiko; Silk, Joseph
2013-01-01
An intermediate mass black hole (IMBH) may have a dark matter (DM) mini-halo around it and develop a spiky structure within less than a parsec from the IMBH. When a stellar mass object is captured by the mini-halo, it eventually infalls into such an IMBH due to gravitational wave back reaction which in turn could be observed directly by future space-borne gravitational wave experiments such as eLISA/NGO. In this paper, we show that the GW detectability strongly depends on the radial profile of the DM distribution. So if the GW is detected, the power index, that is, the DM density distribution would be determined very accurately. The DM density distribution obtained would make it clear how the IMBH has evolved from a seed BH and whether the IMBH has experienced major mergers in the past. Unlike the gamma ray observations of DM annihilation, GW is just sensitive to the radial profile of the DM distribution and even to non-interacting DM. Hence the effect we demonstrate here can be used as a new and powerful pro...
Materials, matter and particles a brief history
Woolfson, Michael M
2010-01-01
This book traces the history of ideas about the nature of matter and also the way that mankind has used material resources that the world offers. Starting with the ideas of ancient civilizations that air, earth, fire and water were the basic ingredients of all matter, it traces the development of the science of chemistry beginning within the ranks of the alchemists. First, the idea of elements grew and then the atomic nature of matter was verified. Physicists had entered the scene, showing the nature of atoms in terms of fundamental particles and then introducing the concept of wave-particle d
More about the q-deformed h-atom wave functions: Normal and abnormal series
International Nuclear Information System (INIS)
The 3-dim quantum Euclidean space and the q-deformed Schroedinger equation are further investigated. The reality condition is taken into account by introducing the right derivatives as well as the left ones. It seems that from the properties of the q-derivatives, corresponding to a fixed ''energy level'' there are infinitive numbers of q deformed wave functions. Among them only one belongs to the normal series, its radial wave function (rwf) has the same number of nodes as that of its classical counterpart. All others have more nodes in their rwf's, and then fall into the abnormal series. This is illustrated by solving the q-Schroedinger equation explicitly for the s-wave solutions. (author). 7 refs
Trapping atoms in the evanescent field of laser written wave guides
Jukic, Dario; Walther, P; Szameit, A; Pohl, T; Götte, J B
2016-01-01
We analyze evanescent fields of laser written waveguides and show that they can be used to trap atoms close to the surface of an integrated optical atom chip. In contrast to subwavelength nanofibres it is generally not possible to create a stable trapping potential using only the fundamental modes. This is why we create a stable trapping potential by using two different laser colors, such that the waveguide supports two modes for the blue detuned laser, while for the red detuned light the waveguide has only a single mode. In particular, we study such a two-color trap for Cesium atoms, and calculate both the potential and losses for the set of parameters that are within experimental reach. We also optimize system parameters in order to minimize trap losses due to photon scattering and tunneling to the surface.
Atomic-scale Electronic Structure of the Cuprate d-Symmetry Form Factor Density Wave State
Hamidian, M. H.; Edkins, S.D.; Kim, Chung Koo; Davis, J. C. Séamus; Mackenzie, A. P.; Eisaki, H.; Uchida, S.; Lawler, M J; Kim, E. -A.; Sachdev, Subir; K. Fujita
2015-01-01
Extensive research into high temperature superconducting cuprates is now focused upon identifying the relationship between the classic 'pseudogap' phenomenon$^{1,2}$ and the more recently investigated density wave state$^{3-13}$. This state always exhibits wave vector $Q$ parallel to the planar Cu-O-Cu bonds$^{4-13}$ along with a predominantly $d$-symmetry form factor$^{14-17}$ (dFF-DW). Finding its microscopic mechanism has now become a key objective$^{18-30}$ of this field. To accomplish th...
E. A. K. Ford; A. L. Aruliah; Griffin, E. M.; I. McWhirter
2008-01-01
Data from the Fabry-Perot Interferometers at KEOPS (Sweden), Sodankyla (Finland), and Svalbard (Norway), have been analysed for gravity wave activity on all the clear nights from 2000 to 2006. A total of 249 nights were available from KEOPS, 133 from Sodankyla and 185 from the Svalbard FPI. A Lomb-Scargle analysis was performed on each of these nights to identify the periods of any wave activity during the night. Comparisons between many nights of data allow the general characteristics of the...
E. A. K. Ford; A. L. Aruliah; Griffin, E. M.; I. McWhirter
2008-01-01
Data from the Fabry-Perot Interferometers at KEOPS (Sweden), Sodankylä (Finland), and Svalbard (Norway), have been analysed for gravity wave activity on all the clear nights from 2000 to 2006. A total of 249 nights were available from KEOPS, 133 from Sodankylä and 185 from the Svalbard FPI. A Lomb-Scargle analysis was performed on each of these nights to identify the periods of any wave activity during the night. Comparisons between many nights of data allow the general char...
International Nuclear Information System (INIS)
Exact localized nonlinear vector matter waves in the form of soliton–soliton and vortex–vortex pairs in two-component Bose–Einstein condensates with spatially modulated nonlinearity coefficients and harmonic trapping potentials are reported. It is shown that there exists an infinite number of exact vector pairs sharing the same chemical potential with soliton–soliton ones for odd integer n while vortex–vortex ones for even integer n. The stability of the vector pairs found is investigated by means of direct numerical simulations and a linear stability analysis; the results show that the stable vortex–vortex pairs (±l,±l) with large topological charges can be supported by the spatially modulated interaction when the harmonic trapping potential is presented in this system. -- Highlights: ► Exact localized nonlinear vector matter waves in two-component Bose–Einstein condensates with spatially modulated nonlinearities are reported. ► An infinite number of exact vector pairs sharing the same chemical potential are presented. ► The stable vortex–vortex pairs (±l,±l) with large topological charges can be supported in this system.
AtomChips: mesoscopic physics with ultracold atoms
International Nuclear Information System (INIS)
Full text: Miniaturization and integration of atom-optical components on atom chips allow coherent manipulation of matter waves on the quantum level by using high spatial resolution electro magnetic potentials from structures on the atom chip or by employing adiabatic radio frequency (RF) or micro wave (MW) potentials. Bose-Einstein condensates (BECs) on these AtomChips can be used for many different tasks. These range from measuring magnetic and electric fields with unprecedented sensitivity by observing the density modulations in trapped highly elongated 1d BECs, to fundamental studies of the universal properties in low dimensional systems like non equilibrium dynamics and coherence decay in one-dimensional super fluids. The talk will give an overview of the recent advances and experiments. (author)
Strong Gaussian standing wave - an efficient tool for laser cooling of atomic beams
Czech Academy of Sciences Publication Activity Database
Zemánek, Pavel; Foot, C. J.
Washington : SPIEThe International Society for Optical Engineering, 1996 - (Nowak, J.; Zajac, M.), s. 97-103 ISSN 0277-786X. [SPIE: Wave and Quantum Aspects of Contemporary Optics. Karpacz (PL), 16.09.1996-20.09.1996] R&D Projects: GA AV ČR IAA2065503 Subject RIV: BH - Optics, Masers, Lasers
International Nuclear Information System (INIS)
The existence of highly spin polarized photoelectrons emitted from non-magnetic solids as well as from unpolarized atoms and molecules has been found to be very common in many studies over the past 40 years. This so-called Fano effect is based upon the influence of the spin-orbit interaction in the photoionization or the photoemission process. In a non-angle-resolved photoemission experiment, circularly polarized radiation has to be used to create spin polarized photoelectrons, while in angle-resolved photoemission even unpolarized or linearly polarized radiation is sufficient to get a high spin polarization. In past years the Rashba effect has become very important in the angle-resolved photoemission of solid surfaces, also with an observed high photoelectron spin polarization. It is the purpose of the present topical review to cross-compare the spin polarization experimentally found in angle-resolved photoelectron emission spectroscopy of condensed matter with that of free atoms, to compare it with the Rashba effect and topological insulators to describe the influence and the importance of the spin-orbit interaction and to show and disentangle the matrix element and phase shift effects therein. The relationship between the energy dispersion of these phase shifts and the emission delay of photoelectron emission in attosecond-resolved photoemission is also discussed. Furthermore the influence of chiral structures of the photo-effect target on the spin polarization, the interferences of different spin components in coherent superpositions in photoemission and a cross-comparison of spin polarization in photoemission from non-magnetic solids with XMCD on magnetic materials are presented; these are all based upon the influence of the spin-orbit interaction in angle-resolved photoemission. (topical review)
International Nuclear Information System (INIS)
This book is written to teach atom structure in very easy way. It is divided into nine chapters, which indicates what is the components of matter? when we divide matter continuously, it becomes atom, what did atom look like? particles comprised of matter is not only atom, discover of particles comprised of atom, symbol of element, various radiation, form alchemy to nuclear transmutation, shape of atom is evolving. It also has various pictures in each chapters to explain easily.
Energy Technology Data Exchange (ETDEWEB)
Lim, Suh Yeon
2006-08-15
This book is written to teach atom structure in very easy way. It is divided into nine chapters, which indicates what is the components of matter? when we divide matter continuously, it becomes atom, what did atom look like? particles comprised of matter is not only atom, discover of particles comprised of atom, symbol of element, various radiation, form alchemy to nuclear transmutation, shape of atom is evolving. It also has various pictures in each chapters to explain easily.
Sine-wave and noise-vocoded sine-wave speech in a tone language: Acoustic details matter.
Rosen, Stuart; Hui, Sze Ngar Catherine
2015-12-01
Sine-wave speech (SWS) is a highly simplified version of speech consisting only of frequency- and amplitude-modulated sinusoids representing the formants. That listeners can successfully understand SWS has led to claims that speech perception must be based on abstract properties of the stimuli far removed from their specific acoustic form. Here it is shown, in bilingual Cantonese/English listeners, that performance with Cantonese SWS is improved by noise vocoding, with no effect on English SWS utterances. This manipulation preserves the abstract informational structure in the signals but changes its surface form. The differential effects of noise vocoding likely arise from the fact that Cantonese is a tonal language and hence more reliant on fundamental frequency (F0) contours for its intelligibility. SWS does not preserve tonal information from the original speech but does have false tonal information signalled by the lowest frequency sinusoid. Noise vocoding SWS appears to minimise the tonal percept, which thus interferes less in the perception of Cantonese. It has no effect in English, which is minimally reliant on F0 variations for intelligibility. Therefore it is not only the informational structure of a sound that is important but also how its acoustic detail interacts with the phonological structure of a given language. PMID:26723325
Schive, Hsi-Yu; Broadhurst, Tom; Huang, Kuan-Wei
2015-01-01
The newly established luminosity functions of high-z galaxies at $4 \\lesssim z \\lesssim 10$ can provide a stringent check on dark matter models that aim to explain the core properties of dwarf galaxies. The cores of dwarf spheroidal galaxies are understood to be too large to be accounted for by free streaming of warm dark matter without overly suppressing the formation of such galaxies. Here we demonstrate with cosmological simulations that wave dark matter, $\\psi$DM, appropriate for light bosons such as axions, does not suffer this problem, given a boson mass of $m_{\\psi} \\ge 1.2 \\times 10^{-22}{\\,\\rm eV}$ ($2\\sigma$). In this case, the halo mass function is suppressed below $\\sim 10^{10}{\\,M_\\odot}$ at a level that is consistent with the high-z luminosity functions, while simultaneously generating the kpc-scale cores in dwarf galaxies arising from the solitonic ground state in $\\psi$DM. We demonstrate that the reionization history in this scenario is consistent with the Thomson optical depth recently report...
75 Years of Matter Wave Louis de Broglie and Renaissance of the Causally Complete Knowledge
Kirilyuk, A P
1999-01-01
A physically real wave associated to any moving particle and propagating in a surrounding material medium was introduced by Louis de Broglie in a series of short notes in 1923 and in the most complete form in his thesis defended in Paris on 25th November 1924. This result gave rise to the whole field of the 'new physics' known today as 'quantum mechanics'. However, although such notions as 'de Broglie wavelength' and 'wave-particle duality' have become 'conventional' in the standard quantum theory, it actually only takes for granted (postulates) the formula for the wavelength (similar to other its formally postulated 'results') and totally ignores the underlying causal, physically real and transparent picture of quantum/wave behaviour outlined by Louis de Broglie in his thesis and further considerably developed in his later works, in the form of 'double solution' and 'hidden thermodynamics' concepts. The payment for such crude deviation from the original realism is the absolute domination of fundamental scien...
Exact traveling wave solutions of the van der Waals normal form for fluidized granular matter
Abourabia, A. M.; Morad, A. M.
2015-11-01
Analytical solutions of the van der Waals normal form for fluidized granular media have been done to study the phase separation phenomenon by using two different exact methods. The Painlevé analysis is discussed to illustrate the integrability of the model equation. An auto-Bäcklund transformation is presented via the truncated expansion and symbolic computation. The results show that the exact solutions of the model introduce solitary waves of different types. The solutions of the hydrodynamic model and the van der Waals equation exhibit a behavior similar to the one observed in molecular dynamic simulations such that two pairs of shock and rarefaction waves appear and move away, giving rise to the bubbles. The dispersion properties and the relation between group and phase velocities of the model equation are studied using the plane wave assumption. The diagrams are drawn to illustrate the physical properties of the exact solutions, and indicate their stability and bifurcation.
Institute of Scientific and Technical Information of China (English)
GUO Jin; MA Jun; SHI Xuehua
2007-01-01
To understand the water purification mechanism of potassium permanganate as a coagulation-aid during the preoxidation process,the microtopography of its reductive products,the newly formed hydrous manganese dioxide and the aged hydrous manganese dioxide,was investigated.The morphology of natural organic matter(NOM)adsorbed by the newly formed hydrous manganese dioxide was also compared with that of NOM alone.By using the tapping mode atomic force microscopy(AFM),the observation results show that the newly formed hydrous manganese dioxide possess a perforated sheet(with a thickness of 0-1.75 nm)as well as some spherical particle structures compared with the hydrous manganese dioxide with 2 h aging time,which demonstrated that the newly formed hydrous manganese dioxide had a large surface area and adsorption capacity.When 1 mmol/L newly formed hydrous manganese dioxide was added,the microtopography of NOM molecules shifted from a loosely dispersed pancake shape(with adsorption height of 5-8.5 nm)to a densely dispersed and uniform spherical structure.These results provide a valid proof that it is the perfect adsorption capability of the newly formed hydrous manganese dioxide that might result in the coagulation aid effect of potassium permanganate preoxidation.
Suppressing decoherence of spin waves in a warm atomic vapor by applying a guiding magnetic field
International Nuclear Information System (INIS)
We report an experimental and theoretical investigation to extend lifetimes of light storages by applying guiding magnetic fields in a room-temperature atomic vapor. The storages are based on dynamic electromagnetically induced transparency. Retrieval efficiencies versus storage time are experimentally measured for different strengths of the guiding magnetic fields. The measured results show that the 1/e storage times are ∼6 μs and ∼59 μs for the guiding field B0z = 0 and B0z = 93 mG, respectively. Physical processes causing decoherence in an atomic ensemble have been discussed and analyzed. A theory model which is used to evaluate the decoherence caused by fluctuations of transverse magnetic fields is developed. Based on this evaluation, the fact that storage lifetimes can be increased by applying guiding magnetic fields is well explained. (paper)
Kinetic-energy matrix elements for atomic Hylleraas-CI wave functions.
Harris, Frank E
2016-05-28
Hylleraas-CI is a superposition-of-configurations method in which each configuration is constructed from a Slater-type orbital (STO) product to which is appended (linearly) at most one interelectron distance rij. Computations of the kinetic energy for atoms by this method have been difficult due to the lack of formulas expressing these matrix elements for general angular momentum in terms of overlap and potential-energy integrals. It is shown here that a strategic application of angular-momentum theory, including the use of vector spherical harmonics, enables the reduction of all atomic kinetic-energy integrals to overlap and potential-energy matrix elements. The new formulas are validated by showing that they yield correct results for a large number of integrals published by other investigators. PMID:27250282
International Nuclear Information System (INIS)
Transition probabilities have been computed using a variational many-electron theory [R. Jauregui, C.F. Bunge, E. Ley-Koo, Phys. Rev. A 55 (1997) 1781] incorporating positive-energy and negative-energy orbitals without ambiguities, and absolutely free from variational collapse. The results agree with experiment and with other calculations based on the no-pair Hamiltonian where ad hoc negative-energy orbitals occur in first-order corrections to the wave functions
Dynamics of atomic spin-orbit-state wave packets produced by short-pulse laser photodetachment
Law, S M K
2016-01-01
We analyse the experiment by Hultgren et al. [Phys. Rev. A {\\bf 87}, 031404 (2013)] on orbital alignment and quantum beats in coherently excited atomic fine-structure manifolds produced by short-pulse laser photodetachment of C$^-$, Si$^-$ and Ge$^-$ negative ions, and derive a formula that describes the beats. Analysis of the experimental data enables us to extract the non-coherent background contribution for each species, and indicates the need for a full density matrix treatment of the problem.
An accurate few-parameter ground state wave function for the Lithium atom
Guevara, Nicolais L; Turbiner, Alexander V
2009-01-01
A simple, seven-parameter trial function is proposed for a description of the ground state of the Lithium atom. It includes both spin functions. Inter-electronic distances appear in exponential form as well as in a pre-exponential factor, and the necessary energy matrix elements are evaluated by numerical integration in the space of the relative coordinates. Encouragingly accurate values of the energy and the cusp parameters are obtained.
A discussion on the double wave theory and its applications to description of radiation atoms
Institute of Scientific and Technical Information of China (English)
LIANG; Fanghao
2001-01-01
［1］Ablowitz, M.J., Carkson, P.A., Nonlinear Evolution and Inverse Scattering., New York: Cambridge University Press, 1991, 47-350.［2］Miura, M.R., Bcklund Transformation, Berlin: Springer_Verlag, 1978, 4-156.［3］Hirota, R., Exact solution of the Korteweg_de Vries equation for multiple collisions of solitons, Phys.Rev.Lett., 1971, 27: 1192-1194.［4］Wang, M.L., Zhou, Y.B., Li, Z.B., Application of a homogeneous balance method to exact solutions of nonlinear equations in mathematical physics, Phys.Lett.A, 1996, 213: 67-75.［5］Shang, Y.D., Explicit and exact solutions for a class of nonlinear wave equations, Acta Appl.Math.Sinica (in Chinese), 2000, 23(1): 21-30.［6］Li, Z.B., Zhang, S.Q., Exact solitary wave equations for nonlinear wave equations using symbolic computation, Acta Math.Phys.Sinica (in Chinese), 1997, 17(1): 81-89.［7］Wu Wenjun, On zeros of algebraic equations: An application of Ritt principle, Kexue Tongbao (Chinese Science Bulletin), 1986, 31(1): 1-5.［8］Heegard, C., Little, J., Saints, K., Systematic encoding via grbner bases fro a class of algebraic geometric codes, IEEE Trans.Inform.Theory, 1995, IT_41: 1752-1761.［9］Conte, R., Musette, M., Link between solitary waves and projective Riccati equation, J.Phys.A: Math.Gen., 1992, 25: 2609-2612.［10］Wahlquist, H.D., Estabrook, F.B., Prolongation structures and nonlinear evolution equations, J.Math.Phys., 1975, 16: 1-7.［11］Whitham, G.B., Linear and Nonlinear Waves, New York: Wiley, 1974, 44.［12］Constantin, P., Foias, C., Nicolaenko, B., Integral Manifolds and Inertial Manifolds for Dissipative Partial Differtial Equations, New York: Springer_Verlag, 1981, 111-118.［13］Chen, S.R., Chen, X.J., Completeness relation of squared Jost functions to the NLS equation, Acta Phys.Sinica (in Chinese), 1999, 48(5): 882-886.
Decay of Langmuir wave in dense plasmas and warm dense matter
Son, S.; Ku, S.; Moon, Sung Joon
2010-01-01
The decays of the Langmuir waves in dense plasmas are computed using the dielectric function theory widely used in the solid state physics. Four cases are considered: a classical plasma, a Maxwellian plasma, a degenerate quantum plasma, and a partially degenerate plasma. The result is considerably different from the conventional Landau damping theory.
International Nuclear Information System (INIS)
Using the F-expansion method we present analytical matter-wave solutions to Bose—Einstein condensates with two- and three-body interactions through the generalized three-dimensional Gross—Pitaevskii equation with time-dependent coefficients, for the periodically time-varying interactions and quadratic potential strength. Such solutions exist under certain conditions, and impose constraints on the functions describing potential strength, nonlinearities, and gain (loss). Various shapes of analytical matter-wave solutions which have important applications of physical interest are studied in details. (general)
Chala, Mikael; Nardini, Germano; Sobolev, Ivan
2016-01-01
A minimal extension of the Standard Model that provides both a dark matter candidate and a strong first-order electroweak phase transition (EWPT) consists of two additional Lorentz and gauge singlets. In this paper we work out a composite Higgs version of this scenario, based on the coset $SO(7)/SO(6)$. We show that by embedding the elementary fermions in appropriate representations of $SO(7)$, all dominant interactions are described by only three free effective parameters. Within the model d...
International Nuclear Information System (INIS)
We report on the delay of optical pulses using electromagnetically induced transparency (EIT) in an ensemble of cold atoms with an optical depth exceeding 500. To identify the regimes in which four-wave mixing (4WM) impacts on EIT behaviour, we conduct the experiment in both 85Rb and 87Rb. Comparison with theory shows excellent agreement in both isotopes. In 87Rb negligible 4WM was observed and we obtained one pulse-width of delay with 50% efficiency. In 85Rb 4WM contributes to the output. In this regime we achieve a delay-bandwidth product of 3.7 at 50% efficiency, allowing temporally multimode delay, which we demonstrate by compressing two pulses into the memory medium. (paper)
Continuous-wave, single-frequency 229 nm laser source for laser cooling of cadmium atoms.
Kaneda, Yushi; Yarborough, J M; Merzlyak, Yevgeny; Yamaguchi, Atsushi; Hayashida, Keitaro; Ohmae, Noriaki; Katori, Hidetoshi
2016-02-15
Continuous-wave output at 229 nm for the application of laser cooling of Cd atoms was generated by the fourth harmonic using two successive second-harmonic generation stages. Employing a single-frequency optically pumped semiconductor laser as a fundamental source, 0.56 W of output at 229 nm was observed with a 10-mm long, Brewster-cut BBO crystal in an external cavity with 1.62 W of 458 nm input. Conversion efficiency from 458 nm to 229 nm was more than 34%. By applying a tapered amplifier (TA) as a fundamental source, we demonstrated magneto-optical trapping of all stable Cd isotopes including isotopes Cd111 and Cd113, which are applicable to optical lattice clocks. PMID:26872168
Sculpting Waves (Presentation Recording)
Engheta, Nader
2015-09-01
In electronics controlling and manipulating flow of charged carriers has led to design of numerous functional devices. In photonics, by analogy, this is done through controlling photons and optical waves. However, the challenges and opportunities are different in these two fields. Materials control waves, and as such they can tailor, manipulate, redirect, and scatter electromagnetic waves and photons at will. Recent development in condensed matter physics, nanoscience, and nanotechnology has made it possible to tailor materials with unusual parameters and extreme characteristics and with atomic precision and thickness. One can now construct structures much smaller than the wavelengths of visible light, thus ushering in unprecedented possibilities and novel opportunities for molding fields and waves at the nanoscale with desired functionalities. At such subwavelength scales, sculpting optical fields and waves provides a fertile ground for innovation and discovery. I will discuss some of the exciting opportunities in this area, and forecast some future directions and possibilities.
Chala, Mikael; Sobolev, Ivan
2016-01-01
A minimal extension of the Standard Model that provides both a dark matter candidate and a strong first-order electroweak phase transition (EWPT) consists of two additional Lorentz and gauge singlets. In this paper we work out a composite Higgs version of this scenario, based on the coset $SO(7)/SO(6)$. We show that by embedding the elementary fermions in appropriate representations of $SO(7)$, all dominant interactions are described by only three free effective parameters. Within the model dependencies of the embedding, the theory predicts one of the singlets to be stable and responsible for the observed dark matter abundance. At the same time, the second singlet introduces new $CP$-violation phases and triggers a strong first-order EWPT, making electroweak baryogenesis feasible. It turns out that this scenario does not conflict with current observations and it is promising for solving the dark matter and baryon asymmetry puzzles. The tight predictions of the model will be accessible at the forthcoming dark ...
Extended adiabatic blast waves and a model of the soft X-ray background. [interstellar matter
Cox, D. P.; Anderson, P. R.
1981-01-01
An analytical approximation is generated which follows the development of an adiabatic spherical blast wave in a homogeneous ambient medium of finite pressure. An analytical approximation is also presented for the electron temperature distribution resulting from coulomb collisional heating. The dynamical, thermal, ionization, and spectral structures are calculated for blast waves of energy E sub 0 = 5 x 10 to the 50th power ergs in a hot low-density interstellar environment. A formula is presented for estimating the luminosity evolution of such explosions. The B and C bands of the soft X-ray background, it is shown, are reproduced by such a model explosion if the ambient density is about .000004 cm, the blast radius is roughly 100 pc, and the solar system is located inside the shocked region. Evolution in a pre-existing cavity with a strong density gradient may, it is suggested, remove both the M band and OVI discrepancies.
Eibenberger, Sandra; Gerlich, Stefan; Arndt, Markus; Mayor, Marcel; Tüxen, Jens
2013-01-01
The quantum superposition principle, a key distinction between quantum physics and classical mechanics, is often perceived as a philosophical challenge to our concepts of reality, locality or space-time since it contrasts our intuitive expectations with experimental observations on isolated quantum systems. While we are used to associating the notion of localization with massive bodies, quantum physics teaches us that every individual object is associated with a wave function that may eventua...
Shock-wave and high strain-rate phenomena in matter: modeling and applications
Scapin, Martina
2013-01-01
The understanding of the material response in case of high strain-rate, impact or shock loading is fundamental in several applications, such as e.g. ballistic, nuclear and military fields. The objective of the investigation of wave propagation in solids is the development of reliable methods for the prediction of dynamic events, such as high velocity or high energy impacts and detonation of explosives. In these events, usually, both high compression and expansion are involved and it is necess...
Observation of a quantum Cheshire Cat in a matter wave interferometer experiment
Denkmayr, Tobias; Geppert, Hermann; Sponar, Stephan; Lemmel, Hartmut; Matzkin, Alexandre; Tollaksen, Jeff; Hasegawa, Yuji
2013-01-01
From its very beginning quantum theory has been revealing extraordinary and counter-intuitive phenomena, such as wave-particle duality, Schr\\"odinger cats and quantum non-locality. In the study of quantum measurement, a process involving pre- and postselection of quantum ensembles in combination with a weak interaction was found to yield unexpected outcomes. This scheme, usually referred to as "weak measurements", can not only be used as an amplification technique and for minimal disturbing m...
Schropp, Andreas; Patommel, Jens; Seiboth, Frank; Arnold, Brice; Galtier, Eric C.; Lee, Hae Ja; Nagler, Bob; Hastings, Jerome B.; Schroer, Christian G.
2012-10-01
Current and upcoming X-ray sources, such as the Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center (SLAC, USA), the SPring-8 Angstrom Compact Free Electron Laser (SACLA, Japan), or the X-ray Free Electron Laser (XFEL, Germany) will provide X-ray beams with outstanding properties.1, 2 Short and intense X-ray pulses of about 50 fs time duration and even shorter will push X-ray science to new frontiers such as, e. g., in high-resolution X-ray imaging, high-energy-density physics or in dynamical studies based on pump-probe techniques. Fast processes in matter often require high-resolution imaging capabilities either by magnified imaging in direct space or diffractive imaging in reciprocal space. In both cases highest resolutions require focusing the X-ray beam.3, 4 In order to further develop high-resolution imaging at free-electron laser sources we are planning a platform to carry out high-resolution phase contrast imaging experiments based on Beryllium compound refractive X-ray lenses (Be-CRLs) at the Matter in Extreme Conditions (MEC) endstation of the LCLS. The instrument provides all necessary equipment to induce high pressure shock waves by optical lasers. The propagation of a shock wave is then monitored with an X-ray Free Electron Laser (FEL) pulse by magnified phase contrast imaging. With the CRL optics, X-ray beam sizes in the sub-100nm range are expected, leading to a similar spatial resolution in the direct coherent projection image. The experiment combines different state-of-the art scientific techniques that are currently available at the LCLS. In this proceedings paper we describe the technical developments carried out at the LCLS in order to implement magnified X-ray phase contrast imaging at the MEC endstation.
THE INTERACTION OF LIGHT AND PARTICLES WITH GRAVITATIONAL WAVES
Trunev A. P.
2014-01-01
In this article we consider a model of the structure of matter, in which elementary particles, atoms and molecules are composed of gravitational waves. A model of interaction of light and particle beams with macroscopic gravitational waves has been proposed. The protocols of experiments to test the theory are considered
THE INTERACTION OF LIGHT AND PARTICLES WITH GRAVITATIONAL WAVES
Directory of Open Access Journals (Sweden)
Trunev A. P.
2014-04-01
Full Text Available In this article we consider a model of the structure of matter, in which elementary particles, atoms and molecules are composed of gravitational waves. A model of interaction of light and particle beams with macroscopic gravitational waves has been proposed. The protocols of experiments to test the theory are considered
Energy Technology Data Exchange (ETDEWEB)
Loth, S.
2007-10-26
This thesis reports measurements of single dopant atoms in III-V semiconductors with low temperature Scanning Tunneling Microscopy (STM) and Scanning Tunneling Spectroscopy (STS). It investigates the anisotropic spatial distribution of acceptor induced tunneling processes at the {l_brace}110{r_brace} cleavage planes. Two different tunneling processes are identified: conventional imaging of the squared acceptor wave function and resonant tunneling at the charged acceptor. A thorough analysis of the tip induced space charge layers identifies characteristic bias windows for each tunnel process. The symmetry of the host crystal's band structure determines the spatial distribution of the tunneling paths for both processes. Symmetry reducing effects at the surface are responsible for a pronounced asymmetry of the acceptor contrasts along the principal [001] axis. Uniaxial strain fields due to surface relaxation and spin orbit interaction of the tip induced electric field are discussed on the basis of band structure calculations. High-resolution STS studies of acceptor atoms in an operating p-i-n diode confirm that an electric field indeed changes the acceptor contrasts. In conclusion, the anisotropic contrasts of acceptors are created by the host crystal's band structure and concomitant symmetry reduction effects at the surface. (orig.)
International Nuclear Information System (INIS)
Zinc sulfide (ZnS) and terbium-doped ZnS (ZnS:Tb) thin films were grown by traveling wave reactor atomic layer epitaxy (ALE). In the present work, ZnCl2, H2S, and tris (2,2,6,6-tetramethyl-3,5-heptandionato) terbium (Tb(tmhd)3) were used as the precursors. The dependence of crystallinity and Cl content of ZnS films was investigated on the growth temperature. ZnS and ZnS:Tb films grown at temperatures ranging from 400 to 500 .deg. C showed a hexagonal-2H crystalline structure. The crystallinity of ZnS film was greatly enhanced as the temperature increased. At growth temperatures higher than 450.deg.C, the films showed preferred orientation with mainly (002) diffraction peak. The Cl content decreased from approximately 9 to 1 at.% with the increase in growth temperature from 400 to 500 .deg. C. The segregation of Cl near the surface region and the incorporation of O from Tb(tmhd)3 during ALE process were also observed using Auger electron spectroscopy. The ALE-grown ZnS and ZnS:Tb films revealed very uniform thickness and smooth surface morphology in the observation using atomic force microscopy and transmission electron microscopy
Atomically smooth hybrid crystalline-core glass-clad fibers for low-loss broadband wave guiding.
Lai, Chien-Chih; Lo, Chia-Yao; Nguyen, Duc Huy; Huang, Jian-Zhi; Tsai, Wan-Shao; Ma, Yuan-Ron
2016-09-01
We demonstrate direct evidence for the first realization of atomically smooth sapphire crystalline fiber cores with a surface variation of only ~1.9 Å. The hybrid glass-clad crystalline cores were grown by a laser-based fiber drawing technique. Because of the improvement in crystal fiber quality, we were able, for the first time, to comprehensively and quantitatively elucidate the correlation between fiber nanostructure and optical loss. We also experimentally demonstrated that high-temperature treatment has a significant impact on defect relaxation and promotes excellent crystallinity, and hence enables low-loss optical wave guiding. The experimentally measured propagation losses in the order of 0.01-0.1 dB/cm are the lowest ever reported among conventional Ti:sapphire channel waveguides and ultrafast-laser-inscribed waveguides, and agree well with the theory. Through experiments and numerical calculation, we have demonstrated that low threshold and high efficiency of Ti:sapphire crystal fiber lasers are possible with the atomic-level roughness, low-loss propagation, and high crystallinity of the Ti:sapphire crystalline core. PMID:27607618
Directory of Open Access Journals (Sweden)
Ahuja Tarushee
2011-04-01
Full Text Available Abstract Arsenic is the toxic element, which creates several problems in human being specially when inhaled through air. So the accurate and precise measurement of arsenic in suspended particulate matter (SPM is of prime importance as it gives information about the level of toxicity in the environment, and preventive measures could be taken in the effective areas. Quality assurance is equally important in the measurement of arsenic in SPM samples before making any decision. The quality and reliability of the data of such volatile elements depends upon the measurement of uncertainty of each step involved from sampling to analysis. The analytical results quantifying uncertainty gives a measure of the confidence level of the concerned laboratory. So the main objective of this study was to determine arsenic content in SPM samples with uncertainty budget and to find out various potential sources of uncertainty, which affects the results. Keeping these facts, we have selected seven diverse sites of Delhi (National Capital of India for quantification of arsenic content in SPM samples with uncertainty budget following sampling by HVS to analysis by Atomic Absorption Spectrometer-Hydride Generator (AAS-HG. In the measurement of arsenic in SPM samples so many steps are involved from sampling to final result and we have considered various potential sources of uncertainties. The calculation of uncertainty is based on ISO/IEC17025: 2005 document and EURACHEM guideline. It has been found that the final results mostly depend on the uncertainty in measurement mainly due to repeatability, final volume prepared for analysis, weighing balance and sampling by HVS. After the analysis of data of seven diverse sites of Delhi, it has been concluded that during the period from 31st Jan. 2008 to 7th Feb. 2008 the arsenic concentration varies from 1.44 ± 0.25 to 5.58 ± 0.55 ng/m3 with 95% confidence level (k = 2.
Institute of Scientific and Technical Information of China (English)
Etienne Wamba; Timoléon C. Kofané; Alidou Mohamadou
2012-01-01
We construct,through a further extension of the tanh-function method,the matter-wave solutions of Bose-Einstein condensates (BECs) with a three-body interaction.The BECs are trapped in a potential comprising the linear magnetic and the time-dependent laser fields.The exact solutions obtained include soliton solutions,such as kink and antikink as well as bright,dark,multisolitonic modulated waves.We realize that the motion and the shape of the solitary wave can be manipulated by controlling the strengths of the fields.
Magnetic polarizability of Rh atoms and spin-waves in FeRh
Energy Technology Data Exchange (ETDEWEB)
Sandratskii, Leonid; Buczek, Pawel; Ernst, Arthur [Max-Planck-Institute of Microstructure Physics, Halle (Germany)
2011-07-01
Recent femtomagnetic experiments revealed a sub-picosecond generation of the magnetisation after laser irradiation of antiferromagnetic FeRh. This strongly enhanced the interest in the magnetic dynamics and thermodynamics of this system. The available first-principles theories of the properties of FeRh outside the ground state differ cardinally in the treatment of magnetic excitations. This, in particular, concerns the account for the appearance of the induced Rh moment in the antiferromagnetic phase and the variable value of the Rh moment in the ferromagnetic phase. We report the calculation of the spin-waves in the antiferromagnetic and ferromagnetic FeRh with account for the specific properties of the Rh moment. The study is performed within both frozen magnon and dynamic susceptibility approaches. The comparison of the results of two approaches is given.
Magnetic polarizability of Rh atoms and spin-waves in FeRh
International Nuclear Information System (INIS)
Recent femtomagnetic experiments revealed a sub-picosecond generation of the magnetisation after laser irradiation of antiferromagnetic FeRh. This strongly enhanced the interest in the magnetic dynamics and thermodynamics of this system. The available first-principles theories of the properties of FeRh outside the ground state differ cardinally in the treatment of magnetic excitations. This, in particular, concerns the account for the appearance of the induced Rh moment in the antiferromagnetic phase and the variable value of the Rh moment in the ferromagnetic phase. We report the calculation of the spin-waves in the antiferromagnetic and ferromagnetic FeRh with account for the specific properties of the Rh moment. The study is performed within both frozen magnon and dynamic susceptibility approaches. The comparison of the results of two approaches is given.
The Expectation Value of S(1).S(2)-Wave Functions Don't Matter
Zamick, L
2016-01-01
We consider the expectation value of the quantity [3+ \\sigma (1).\\sigma(2)]/4 . This has a value +1 for 2 nucleons with spin S=! and zero for S=0. We show that for the jj coupling 2 particle configuration [j(1) j(2)]^{J} the expectation value has the structure A+B J(J+1) where A and B are constants. We then show that for a 2proton-2neutron configuration with total angular momentum J=0 the expectation value is independent of the details of the wave function.This is also true for J=1 and we get the same expectation value as for J=0.
Does direct impact of SST on short wind waves matter for scatterometry?
Grodsky, Semyon A.; Kudryavtsev, Vladimir N.; Bentamy, Abderrahim; Carton, James A.; Chapron, Bertrand
2012-01-01
Scatterometer radar backscatter depends on the relationship linking surface stress and surface roughness. SST can alter the growth rate of centimeter-scale waves through its impact on air and water density and water viscosity. This SST-dependency has not been included in the standard Geophysical Model Functions. This study uses a radar imaging model to evaluate this SST-dependence and compares the results to observations from QuikScat Ku-band and ASCAT C-band scatterometers. A SST correction ...