Strong Coupling and Classicalization
Dvali, Gia
2016-01-01
Classicalization is a phenomenon in which a theory prevents itself from entering into a strong-coupling regime, by redistributing the energy among many weakly-interacting soft quanta. In this way, the scattering process of some initial hard quanta splits into a large number of soft elementary processes. In short, the theory trades the strong coupling for a high-multiplicity of quanta. At very high energies, the outcome of such a scattering experiment is a production of soft states of high occupation number that are approximately classical. It is evident that black hole creation in particle collision at super-Planckian energies is a result of classicalization, but there is no a priory reason why this phenomenon must be limited to gravity. If the hierarchy problem is solved by classicalization, the LHC has a chance of detecting a tower of new resonances. The lowest-lying resonances must appear right at the strong coupling scale in form of short-lived elementary particles. The heavier members of the tower must b...
Classical Integrability for Three-point Functions: Cognate Structure at Weak and Strong Couplings
Kazama, Y; Nishimura, T
2016-01-01
In this paper, we develop a new method of computing three-point functions in the SU(2) sector of the $\\mathcal{N}=4$ super Yang-Mills theory in the semi-classical regime at weak coupling, which closely parallels the strong coupling analysis. The structure threading two disparate regimes is the so-called monodromy relation, an identity connecting the three-point functions with and without the insertion of the monodromy matrix. We shall show that this relation can be put to use directly for the semi-classical regime, where the dynamics is governed by the classical Landau-Lifshitz sigma model. Specifically, it reduces the problem to a set of functional equations, which can be solved once the analyticity in the spectral parameter space is specified. To determine the analyticity, we develop a new universal logic applicable at both weak and strong couplings. As a result, compact semi-classical formulas are obtained for a general class of three-point functions at weak coupling including the ones whose semi-classical...
Kinetic theory of the shear viscosity of a strongly coupled classical one-component plasma
We present an approximation to the linearized collision operator or memory function of the exact kinetic equation obeyed by the correlation function of the phase-space density of a classical one-component plasma. This approximate collision operator generalizes the well known Balescu-Guernsey-Lenard (BGL) operator to finite wavelengths, finite frequencies, and finite coupling constants. It, moreover, satisfies the necessary symmetry relations, leads to appropriate conservation laws, and fulfills its first sum rule exactly. Next we use this operator to compute the shear viscosity eta for a series of coupling constants spanning the whole fluid phase. For weak coupling we make contact with the BGL theory, while for strong coupling we confirm, at least qualitatively, the results of Vieillefosse and Hansen, who predicted a minimum in eta as a function of temperature. We also demonstrate the important role played by the sum rules in the quantitative evaluation of a transport coefficient such as eta
A self-consistent approximation scheme is formulated for the calculation of the dynamical linear polarizability of classical electron monolayers. The derivation is carried out in two stages. In the first stage, the authors formulate a simple response function relation linking linear and quadratic polarizabilities; the dynamical coupling function is expressed entirely in terms of the latter. The basic elements in the derivation are the first BBGKY kinetic equation (prepared in the velocity average approximation) and the non-linear fluctuation-dissipation theorem. The new response function relation is exact at zero frequency and exactly satisfies the third frequency moment sum rule. In the second stage, self-consistency is guaranteed by approximating the quadratic polarizability in terms of linear ones. The theory is examined in the weak coupling limit where it is found that a dominant γ-independent non-RPA contribution to the damping is missing. The structure of the missing term is identified at arbitrary coupling strengths. Work is in progress to see how it can be incorporated into the approximation scheme. (author)
Strong-coupling approximations
Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi4 field theory in 1 + 1 dimensions. 9 references, 6 figures
Eikonal Scattering at Strong Coupling
Irizarry-Gelpi, Melvin Eloy
The scattering of subatomic particles is a source of important physical phenomena. Decades of work have yielded many techniques for the computation of scattering amplitudes. Most of these techniques involve perturbative quantum field theory and thus apply only at weak coupling. Complementary to scattering is the formation of bound states, which are intrinsically nonperturbative. Regge theory arose in the late 1950s as an attempt to describe, with a single framework, both scattering and the formation of bound states. In Regge theory one obtains an amplitude with bound state poles after analytic continuation of a nonperturbative scattering amplitude, corresponding to a sum of an infinite number of Feynman diagrams at large energy and fixed momentum transfer (but with crossed kinematics). Thus, in order to obtain bound states at fixed energy, one computes an amplitude at large momentum transfer. In this dissertation we calculate amplitudes with bound states in the regime of fixed energy and small momentum transfer. We formulate the elastic scattering problem in terms of many-body path integrals, familiar from quantum mechanics. Then we invoke the semiclassical JWKB approximation, where the path integral is dominated by classical paths. The dynamics in the semiclassical regime are strongly coupled, as found by Halpern and Siegel. When the momentum transfer is small, the classical paths are simple straight lines and the resulting semiclassical amplitudes display a spectrum of bound states that agrees with the spectrum found by solving wave equations with potentials. In this work we study the bound states of matter particles with various types of interactions, including electromagnetic and gravitational interactions. Our work has many analogies with the work started by Alday and Maldacena, who computed scattering amplitudes of gluons at strong coupling with semiclassical quantum mechanics of strings in anti de-Sitter spacetime. We hope that in the future we can apply our
Driven classical diffusion with strong correlated disorder
Pryadko, Leonid P.; Lin, Jing-Xian
2004-01-01
We analyze one-dimensional motion of an overdamped classical particle in the presence of external disorder potential and an arbitrary driving force F. In thermodynamical limit the effective force-dependent mobility mu(F) is self-averaging, although the required system size may be exponentially large for strong disorder. We calculate the mobility mu(F) exactly, generalizing the known results in linear response (weak driving force) and the perturbation theory in powers of the disorder amplitude...
Gluon scattering amplitudes at strong coupling
Alday, Luis F
2007-01-01
We describe how to compute planar gluon scattering amplitudes at strong coupling in N=4 super Yang Mills by using the gauge/string duality. The computation boils down to finding a certain classical string configuration whose boundary conditions are determined by the gluon momenta. The results are infrared divergent. We introduce the gravity version of dimensional regularization to define finite quantities. The leading and subleading IR divergencies are characterized by two functions of the coupling that we compute at strong coupling. We compute also the full finite form for the four point amplitude and we find agreement with a recent ansatz by Bern, Dixon and Smirnov.
Circuit electromechanics with single photon strong coupling
In circuit electromechanics, the coupling strength is usually very small. Here, replacing the capacitor in circuit electromechanics by a superconducting flux qubit, we show that the coupling among the qubit and the two resonators can induce effective electromechanical coupling which can attain the strong coupling regime at the single photon level with feasible experimental parameters. We use dispersive couplings among two resonators and the qubit while the qubit is also driven by an external classical field. These couplings form a three-wave mixing configuration among the three elements where the qubit degree of freedom can be adiabatically eliminated, and thus results in the enhanced coupling between the two resonators. Therefore, our work constitutes the first step towards studying quantum nonlinear effect in circuit electromechanics
Circuit electromechanics with single photon strong coupling
Xue, Zheng-Yuan, E-mail: zyxue@scnu.edu.cn; Yang, Li-Na [Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Zhou, Jian, E-mail: jianzhou8627@163.com [Department of Electronic Communication Engineering, Anhui Xinhua University, Hefei 230088 (China); Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China)
2015-07-13
In circuit electromechanics, the coupling strength is usually very small. Here, replacing the capacitor in circuit electromechanics by a superconducting flux qubit, we show that the coupling among the qubit and the two resonators can induce effective electromechanical coupling which can attain the strong coupling regime at the single photon level with feasible experimental parameters. We use dispersive couplings among two resonators and the qubit while the qubit is also driven by an external classical field. These couplings form a three-wave mixing configuration among the three elements where the qubit degree of freedom can be adiabatically eliminated, and thus results in the enhanced coupling between the two resonators. Therefore, our work constitutes the first step towards studying quantum nonlinear effect in circuit electromechanics.
Kinetic Mixing at Strong Coupling
Del Zotto, Michele; Kumar, Piyush; Malekian, Arada; Wecht, Brian
2016-01-01
A common feature of many string-motivated particle physics models is additional strongly coupled U(1)'s. In such sectors, electric and magnetic states have comparable mass, and integrating out modes also charged under U(1) hypercharge generically yields CP preserving electric kinetic mixing and CP violating magnetic kinetic mixing terms. Even though these extra sectors are strongly coupled, we show that in the limit where the extra sector has approximate N = 2 supersymmetry, we can use formal methods from Seiberg-Witten theory to compute these couplings. We also calculate various quantities of phenomenological interest such as the cross section for scattering between visible sector states and heavy extra sector states, as well as the effects of supersymmetry breaking induced from coupling to the MSSM.
Existence of a strong coupling phase in QED has been suggested in solutions of the Schwinger-Dyson equation and in Monte Carlo simulation of lattice QED. In this article we recapitulate the previous arguments, and formulate the problem in the modern framework of the renormalization theory, Wilsonian renormalization. This scheme of renormalization gives the best understanding of the basic structure of a field theory especially when it has a multi-phase structure. We resolve some misleading arguments in the previous literature. Then we set up a strategy to attack the strong phase, if any. We describe a trial; a coupled Schwinger-Dyson equation. Possible picture of the strong coupling phase QED is presented. (author)
Nonperturbative enhancement of superloop at strong coupling
Belitsky, A V
2015-01-01
We address the near-collinear expansion of NMHV six-particle scattering amplitudes at strong value of 't Hooft coupling in planar maximally supersymmetric Yang-Mills theory. We complement recent studies of this observable within the context of the pentagon operator product expansion, via the dual super Wilson loop description, by studying effects of multiple scalar exchanges that accompany (or not) massive flux-tube excitations. Due to the fact that holes have a very small, nonperturbatively generated mass which is exponentially suppressed in 't Hooft coupling, their exchanges must be resummed in the ultraviolet limit. This procedure yields a contribution to the expectation value of the superloop which enters on equal footing with the classical area, --- a phenomenon which was earlier observed for MHV amplitudes. In all components, the near-massless scalar exchanges factorize from the ones of massive particles, at leading order in strong coupling.
PREFACE: Strongly Coupled Coulomb Systems Strongly Coupled Coulomb Systems
Neilson, David; Senatore, Gaetano
2009-05-01
This special issue contains papers presented at the International Conference on Strongly Coupled Coulomb Systems (SCCS), held from 29 July-2 August 2008 at the University of Camerino. Camerino is an ancient hill-top town located in the Apennine mountains of Italy, 200 kilometres northeast of Rome, with a university dating back to 1336. The Camerino conference was the 11th in a series which started in 1977: 1977: Orleans-la-Source, France, as a NATO Advanced Study Institute on Strongly Coupled Plasmas (hosted by Marc Feix and Gabor J Kalman) 1982: Les Houches, France (hosted by Marc Baus and Jean-Pierre Hansen) 1986: Santa Cruz, California, USA (hosted by Forrest J Rogers and Hugh E DeWitt) 1989: Tokyo, Japan (hosted by Setsuo Ichimaru) 1992: Rochester, New York, USA (hosted by Hugh M Van Horn and Setsuo Ichimaru) 1995: Binz, Germany (hosted by Wolf Dietrich Kraeft and Manfred Schlanges) 1997: Boston, Massachusetts, USA (hosted by Gabor J Kalman) 1999: St Malo, France (hosted by Claude Deutsch and Bernard Jancovici) 2002: Santa Fe, New Mexico, USA (hosted by John F Benage and Michael S Murillo) 2005: Moscow, Russia (hosted by Vladimir E Fortov and Vladimir Vorob'ev). The name of the series was changed in 1996 from Strongly Coupled Plasmas to Strongly Coupled Coulomb Systems to reflect a wider range of topics. 'Strongly Coupled Coulomb Systems' encompasses diverse many-body systems and physical conditions. The purpose of the conferences is to provide a regular international forum for the presentation and discussion of research achievements and ideas relating to a variety of plasma, liquid and condensed matter systems that are dominated by strong Coulomb interactions between their constituents. Each meeting has seen an evolution of topics and emphases that have followed new discoveries and new techniques. The field has continued to see new experimental tools and access to new strongly coupled conditions, most recently in the areas of warm matter, dusty plasmas
PREFACE: Strongly Coupled Coulomb Systems
Fortov, Vladimir E.; Golden, Kenneth I.; Norman, Genri E.
2006-04-01
This special issue contains papers presented at the International Conference on Strongly Coupled Coulomb Systems (SCCS) which was held during the week of 20 24 June 2005 in Moscow, Russia. The Moscow conference was the tenth in a series of conferences. The previous conferences were organized as follows. 1977: Orleans-la-Source, France, as a NATO Advanced Study Institute on Strongly Coupled Plasmas (organized by Marc Feix and Gabor J Kalman) 1982: Les Houches, France (organized by Marc Baus and Jean-Pierre Hansen) 1986: Santa Cruz, California, USA (hosted by Forrest J Rogers and Hugh E DeWitt) 1989: Tokyo, Japan (hosted by Setsuo Ichimaru) 1992: Rochester, NY, USA (hosted by Hugh M Van Horn and Setsuo Ichimaru) 1995: Binz, Germany (hosted by Wolf Dietrich Kraeft and Manfred Schlanges) 1997: Boston, Massachusetts, USA (hosted by Gabor J Kalman) 1999: St Malo, France (hosted by Claude Deutsch and Bernard Jancovici) 2002: Santa Fe, New Mexico, USA (hosted by John F Benage and Michael S Murillo) After 1995 the name of the series was changed from `Strongly Coupled Plasmas' to the present name in order to extend the topics of the conferences. The planned frequency for the future is once every three years. The purpose of these conferences is to provide an international forum for the presentation and discussion of research accomplishments and ideas relating to a variety of plasma liquid and condensed matter systems, dominated by strong Coulomb interactions between their constituents. Strongly coupled Coulomb systems encompass diverse many-body systems and physical conditions. Each meeting has seen an evolution of topics and emphasis as new discoveries and new methods appear. This year, sessions were organized for invited presentations and posters on dense plasmas and warm matter, astrophysics and dense hydrogen, non-neutral and ultracold plasmas, dusty plasmas, condensed matter 2D and layered charged-particle systems, Coulomb liquids, and statistical theory of SCCS. Within
Fluctuations in strongly coupled cosmologies
Bonometto, Silvio A
2013-01-01
In the early Universe, a dual component made of coupled CDM and a scalar field $\\Phi$, if their coupling $\\beta > \\sqrt{3}/2$, owns an attractor solution, making them a stationary fraction of cosmic energy during the radiation dominated era. Along the attractor, both such components expand $\\propto a^{-4}$ and have early density parameters $\\Omega_{d} = 1/ (4\\beta^2)$ and $\\Omega_c= 2, \\Omega_d$ (field and CDM, respectively). In a previous paper it was shown that, if a further component, expanding $\\propto a^{-3}$, breaks such stationary expansion at $z \\sim 3$--$5 \\times 10^3$, cosmic components gradually acquire densities consistent with observations. This paper, first of all, considers the case that this component is warm. However, its main topic is the analysis of fluctuation evolution: out of horizon modes are then determined; their entry into horizon is numerically evaluated as well as the dependence of Meszaros effect on the coupling $\\beta$; finally, we compute: (i) transfer function and linear spectr...
Strong coupling electroweak symmetry breaking
Barklow, T.L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Burdman, G. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Chivukula, R.S. [Boston Univ., MA (United States). Dept. of Physics
1997-04-01
The authors review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. They emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. They also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models.
Thermal conductivity of a strongly coupled hydrogen plasma
''Molecular Dynamics'' simulations has been used to compute the thermal conductivity of the strongly coupled, nearly classical hydrogen plasma. The relaxation of a suitably defined heat current is significantly faster than the decay of the microscopic electric current. Electrical and thermal conductivities are not related by a simple Wiedemann-Franz law in the dense plasma
Strongly-coupled nanotube electromechanical resonators
Deng, Guang-Wei; ZHU Dong; Wang, Xin-He; Zou, Chang-Ling; Wang, Jiang-Tao; Li, Hai-Ou; Cao, Gang; Liu, Di; Li, Yan; Xiao, Ming; Guo, Guang-Can; Jiang, Kai-Li; Dai, Xing-Can; Guo, Guo-Ping
2016-01-01
Coupling an electromechanical resonator with carbon-nanotube quantum dots is a significant method to control both the electronic charge and the spin quantum states. By exploiting a novel micro-transfer technique, we fabricate two strongly-coupled and electrically-tunable mechanical resonators on a single carbon nanotube for the first time. The frequency of the two resonators can be individually tuned by the bottom gates, and strong coupling is observed between the electron charge and phonon m...
Stopping Power for Strong Beam-Plasma Coupling
Gericke, Dirk O.
2001-10-01
The slowing down process of charged particles in plasma targets is investigated for the case of strong beam-plasma coupling. Strong beam-plasma correlations can be considered using the collision operator of the quantum Boltzmann equation. As a first step, dynamic screening is included in the first Born approximation. This approach gives good results for moderate beam-plasma coupling (Zb Γ^3/2 Bethe-formula, the standard model of the stopping power (Bethe plus Bloch corrections and Barkas terms), the Li & Petrasso formula and simulation data (MD and PIC), is given. This comparison clearly shows the advantage of the proposed model: it smoothly interpolates between the classical low velocity regime, where strong coupling effects occur, and the high velocity quantum regime, where collective modes are important. In the latter case, the experimentally proven Bethe-formula is obtained. Furthermore, it matches the simulation data for moderate as well as strong beam-plasma coupling.
From individual to strongly coupled metallic nanocavities
Salomon, Adi; Kolkowski, Radoslaw; Zyss, Joseph
2013-01-01
Localized plasmonic modes of metallic nanoparticles may hybridize like those of atoms forming a molecule. However, the rapid decay of the plasmonic fields outside the metal severely limits the range of these interactions to tens of nanometers. Herein, we demonstrate very strong coupling of nanocavities in metal films, sparked by propagating surface plasmons and evident even at much larger distances of hundreds of nanometers for the properly selected metal/wavelength combination. Such strong coupling drastically changes the symmetry of the charge distribution around the nanocavities making it amenable to probing by the nonlinear optical response of the medium. We show that when strongly coupled, equilateral triangular nanocavities lose their individual three-fold symmetry to adopt the lower symmetry of the coupled system and then respond like a single dipolar entity. A quantitative model is suggested for the transition from individual to strongly coupled nanocavities.
Classical Coupled Mode Theory of Optomechanical Crystals
Khorasani, Sina
2016-01-01
Acousto-optic interaction in optomechanical crystals allows unidirectional control of elastic waves over optical waves. However, as a result of this nonlinear interaction, infinitely many optical modes are born. This article presents an exact formulaion of coupled mode theory for interaction between elastic Bloch wave waves and photonic Bloch waves moving in a phonotonic waveguide. In general, an optical wavefront is strongly diffracted by an elastic wave in frequency and wavevector, and thus infinite modes with different frequencies and wavevectors appear. We discuss resonance and mode conversion conditions, and present a rigorous method to derive coupling rates and mode profiles. We also find a conservation law which rules over total optical power from interacting individual modes. Modifications of the theory to phonotonic cavities are also discussed. We present application examples including switch, frequency shifter, and reflector.
Strong Coupling between Plasmons and Organic Semiconductors
Joel Bellessa
2014-05-01
Full Text Available In this paper we describe the properties of organic material in strong coupling with plasmon, mainly based on our work in this field of research. The strong coupling modifies the optical transitions of the structure, and occurs when the interaction between molecules and plasmon prevails on the damping of the system. We describe the dispersion relation of different plasmonic systems, delocalized and localized plasmon, coupled to aggregated dyes and the typical properties of these systems in strong coupling. The modification of the dye emission is also studied. In the second part, the effect of the microscopic structure of the organics, which can be seen as a disordered film, is described. As the different molecules couple to the same plasmon mode, an extended coherent state on several microns is observed.
Holographic equilibration at strong and intermediate coupling
Vuorinen, Aleksi [Helsinki Institute of Physics and Department of Physics, P.O. Box 64, FI-00014 University of Helsinki (Finland)
2016-01-22
In these conference proceedings, I will descibe recent developments in the study of thermalization dynamics in strongly, but not infinitely strongly coupled field theories using holography. After reviewing the main tools required in these calculations, I will introduce a set of central results, discuss their physical implications, and finally outline a number of challenges to be tackled in the future.
Strong Coupling Gauge Theories in LHC ERA
Fukaya, H.; Harada, M.; Tanabashi, M.; Yamawaki, K.
2011-01-01
Higgs, or techni-dilaton - composite Higgs near conformality / Koichi Yamawaki -- Phase diagram of strongly interacting theories / Francesco Sannino -- Resizing conformal windows / O. Antipin and K. Tuominen -- Nearly conformal gauge theories on the lattice / Zoltan Fodor ... [et al.] -- Going beyond QCD in lattice gauge theory / G. T. Fleming -- Phases of QCD from small to large N[symbol]: (some) lattice results / A. Deuzeman, E. Pallante and M. P. Lombardo -- Lattice gauge theory and (quasi)-conformal technicolor / D. K. Sinclair and J. B. Kogut -- Study of the running coupling constant in 10-flavor QCD with the Schrodinger functional method / N. Yamada ... [et al.] -- Study of the running coupling in twisted Polyakov scheme / T. Aoyama ... [et al.].Running coupling in strong gauge theories via the lattice / Zoltan Fodor ... [et al.] -- Higgsinoless supersymmetry and hidden gravity / Michael L. Graesser, Ryuichiro Kitano and Masafumi Kurachi -- The latest status of LHC and the EWSB physics / S. Asai -- Continuum superpartners from supersymmetric unparticles / Hsin-Chia Cheng -- Review of minimal flavor constraints for technicolor / Hidenori S. Fukano and Francesco Sannino -- Standard model and high energy Lorentz violation / Damiano Anselmi -- Dynamical electroweak symmetry breaking and fourth family / Michio Hashimoto -- Holmorphic supersymmetric Nambu-Jona-Lasino model and dynamical electroweak symmetry breaking / Dong-Won Jung, Otto C. W. Kong and Jae Sik Lee -- Ratchet model of Baryogenesis / Tatsu Takeuchi, Azusa Minamizaki and Akio Sugamoto -- Classical solutions of field equations in Einstein Gauss-Bonnet gravity / P. Suranyi, C. Vaz and L. C. R. Wijewardhana -- Black holes constitute all dark matter / Paul H. Frampton -- Electroweak precision test and Z [symbol] in the three site Higgsless model / Tomohiro Abe -- Chiral symmetry and BRST symmetry breaking, quaternion reality and the lattice simulation / Sadataka Furui -- Holographic techni-dilaton, or
Probing attosecond kinetic physics in strongly coupled plasmas
The interaction of intense laser pulses with noble gas clusters is investigated by a molecular dynamics analysis. We find that the strength of electron-ion coupling in the created nanoplasmas (Γei), and thus the collisional properties, can be controlled by a single parameter: the laser intensity. Varying the intensity from 1016 to 2 x 1014 W cm-2 results in nanoplasmas with Γei between 0.1 and 1. This spans the range of classical kinetic physics, from weakly coupled plasmas dominated by collective behaviour, to strongly coupled plasmas dominated by collisions. In combination with recent advances in ultrafast technology, this opens novel avenues for a systematic investigation of collective and collision processes in strongly coupled plasmas, taking place on sub-femtosecond time scales
Theoretical Properties of the Entanglement in a Strong Coupling Region
Ma, Chen-Te
2016-01-01
Entanglement entropy is expected to do a suitable order parameter to classify phase structures at zero temperature. Thus, it is interesting to understand theoretical properties of the entanglement entropy in a strong coupling region. We compute entropy in a non-relativistic model with four fermion interactions and spin imbalance in four dimensional lattice with an infinite fermion mass limit from an exact effective potential to obtain the behavior of the entropy in infinite strong coupling limit. The result is zero in infinite strong coupling and finite lattice spacing. The result supports non-trivial topology needs to be considered in the entanglement entropy. We consider two dimensions to know the lattice artifact, and quantum gravity problems. The entanglement entropy in two dimensional gravity theory is the sum of the classical Shannon entropy and usual expectation values of area term. We also use area law to do the necessary condition in quantum gravity theory to argue translational invariance should be ...
Strong coupling between surface plasmon polaritons and emitters: a review
Törmä, P.; Barnes, W. L.
2015-01-01
In this review we look at the concepts and state-of-the-art concerning the strong coupling of surface plasmon-polariton modes to states associated with quantum emitters such as excitons in J-aggregates, dye molecules and quantum dots. We explore the phenomenon of strong coupling with reference to a number of examples involving electromagnetic fields and matter. We then provide a concise description of the relevant background physics of surface plasmon polaritons. An extensive overview of the historical background and a detailed discussion of more recent relevant experimental advances concerning strong coupling between surface plasmon polaritons and quantum emitters is then presented. Three conceptual frameworks are then discussed and compared in depth: classical, semi-classical and fully quantum mechanical; these theoretical frameworks will have relevance to strong coupling beyond that involving surface plasmon polaritons. We conclude our review with a perspective on the future of this rapidly emerging field, one we are sure will grow to encompass more intriguing physics and will develop in scope to be of relevance to other areas of science.
Strongly Coupled Quark Gluon Plasma (SCQGP)
Bannur, Vishnu M.
2005-01-01
We propose that the reason for the non-ideal behavior seen in lattice simulation of quark gluon plasma (QGP) and relativistic heavy ion collisions (URHICs) experiments is that the QGP near T_c and above is strongly coupled plasma (SCP), i.e., strongly coupled quark gluon plasma (SCQGP). It is remarkable that the widely used equation of state (EoS) of SCP in QED (quantum electrodynamics) very nicely fits lattice results on all QGP systems, with proper modifications to include color degrees of ...
Strong-coupling diffusion in relativistic systems
Georg Wolschin
2003-05-01
Different from the early universe, heavy-ion collisions at very high energies do not reach statistical equilibrium, although thermal models explain many of their features. To account for nonequilibrium strong-coupling effects, a Fokker–Planck equation with time-dependent diffusion coefﬁcient is proposed. A schematic model for rapidity distributions of participant baryons is set up and solved analytically. The evolution from SIS via AGS and SPS to RHIC energies is discussed. Strong-coupling diffusion produces double-peaked spectra in central collisions at the higher SPS momentum of 158 A$\\cdot$GeV/c and beyond.
Nonlinear Super Integrable Couplings of Super Classical-Boussinesq Hierarchy
Xiuzhi Xing
2014-01-01
Full Text Available Nonlinear integrable couplings of super classical-Boussinesq hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then, its super Hamiltonian structures were established by using super trace identity. As its reduction, nonlinear integrable couplings of the classical integrable hierarchy were obtained.
Dielectric tensor of strongly coupled plasmas
Complex conductivity and dielectric permeability tensors of strongly coupled plasmas are studied and constructed on the basis of exact relations and sum rules. Both Coulomb and magnetic correlation are taken into account. The electromagnetic mode dispersion law is studied. The magnetostatic properties of a system of charged particles are investigated in detail. 26 refs
Collective excitations in strongly coupled ultra-relativistic plasmas
In the collective mode spectrum of a relativistic, strongly coupled plasma, novel physical effects emerge, which are absent both in the weakly coupled relativistic and in the strongly coupled non-relativistic plasmas. Inspired by the pseudo-relativistic behavior of the electron gas in two-dimensional graphene layers, we address the problem of a classical two-dimensional, ultra-relativistic system of charged particles. We investigate the mode dispersion and damping both through molecular dynamics simulations and analytically via the quasi-localized charge approximation and develop modifications of the theory appropriate for this system. The new aspect introduced in the simulation is the decoupling of particle velocities from the particle momenta. As for new physical features, their origin is to be sought in the constancy of particle speeds and in the broad distribution of 'plasma frequencies', mimicking the similar distribution of momenta is causing the system to emulate the behavior of a collection of an infinite number of oscillators. Of particular interest is the strongly reduced damping at weak coupling, brought about by the disappearance of the Landau damping and the greatly enhanced damping at strong coupling, caused by the phase mixing of the coupled plasma oscillators. We suggest the possible experimental detection of these effects in graphene
Strongly Coupled Quark Gluon Plasma (SCQGP)
Bannur, V M
2006-01-01
We propose that the reason for the non-ideal behavior seen in lattice simulation of quark gluon plasma (QGP) and relativistic heavy ion collisions (URHICs) experiments is that the QGP near T_c and above is strongly coupled plasma (SCP), i.e., strongly coupled quark gluon plasma (SCQGP). It is remarkable that the widely used equation of state (EoS) of SCP in QED (quantum electrodynamics) very nicely fits lattice results on all QGP systems, with proper modifications to include color degrees of freedom and running coupling constant. Results on pressure in pure gauge, 2-flavors and 3-flavors QGP, are all can be explained by treating QGP as SCQGP as demonstated here.Energy density and speed of sound are also presented for all three systems.
Patterns of Strong Coupling for LHC Searches
Liu, Da; Rattazzi, Riccardo; Riva, Francesco
2016-01-01
Even though the Standard Model (SM) is weakly coupled at the Fermi scale, a new strong dynamics involving its degrees of freedom may conceivably lurk at slightly higher energies, in the multi TeV range. Approximate symmetries provide a structurally robust context where, within the low energy description, the dimensionless SM couplings are weak, while the new strong dynamics manifests itself exclusively through higher-derivative interactions. We present an exhaustive classification of such scenarios in the form of effective field theories, paying special attention to new classes of models where the strong dynamics involves, along with the Higgs boson, the SM gauge bosons and/or the fermions. The IR softness of the new dynamics suppresses its effects at LEP energies, but deviations are in principle detectable at the LHC, even at energies below the threshold for production of new states. Our construction provides the so far unique structurally robust context where to motivate several searches in Higgs physics, d...
Linearly Coupled Directed Percolation in the Strong Coupling Regime
DENGLER, R.
2004-01-01
We consider directed percolation processes for particle types A and B coupled unidirectionally by a transmutation reaction A -> B. It is shown that the strong coupling regime of this recently introduced problem defines a universality class with upper critical dimension d=6. Exact expressions are derived for the scaling dimensions in the inactive phase above d=4. Below d=4 the interactions of the normal directed percolation also get relevant.
Holographic gauge mediation via strongly coupled messengers
We consider a relative of semidirect gauge mediation where the hidden sector exists at large 't Hooft coupling. Such scenarios can be difficult to describe using perturbative field theory methods but may fall into the class of holographic gauge mediation scenarios, meaning that they are amenable to the techniques of gauge/gravity duality. We use a recently found gravity solution to examine one such case, where the hidden sector is a cascading gauge theory resulting in a confinement scale not much smaller than the messenger mass. In the original construction of holographic gauge mediation, as in other examples of semidirect gauge mediation at strong coupling, the primary contributions to visible sector soft terms come from weakly coupled messenger mesons. In contrast to these examples, we describe the dual of a gauge theory where there are significant contributions from scales in which the strongly coupled messenger quarks are the effective degrees of freedom. In this regime, the visible sector gaugino mass can be calculated entirely from holography.
Strongly coupled models at the LHC
In this thesis strongly coupled models where the Higgs boson is composite are discussed. These models provide an explanation for the origin of electroweak symmetry breaking including a solution for the hierarchy problem. Strongly coupled models provide an alternative to the weakly coupled supersymmetric extensions of the Standard Model and lead to different and interesting phenomenology at the Large Hadron Collider (LHC). This thesis discusses two particular strongly coupled models, a composite Higgs model with partial compositeness and the Littlest Higgs model with T-parity - a composite model with collective symmetry breaking. The phenomenology relevant for the LHC is covered and the applicability of effective operators for these types of strongly coupled models is explored. First, a composite Higgs model with partial compositeness is discussed. In this model right-handed light quarks could be significantly composite, yet compatible with experimental searches at the LHC and precision tests on Standard Model couplings. In these scenarios, which are motivated by flavour physics, large cross sections for the production of new resonances coupling to light quarks are expected. Experimental signatures of right-handed compositeness at the LHC are studied, and constraints on the parameter space of these models are derived using recent results by ATLAS and CMS. Furthermore, dedicated searches for multi-jet signals at the LHC are proposed which could significantly improve the sensitivity to signatures of right-handed compositeness. The Littlest Higgs model with T-parity, providing an attractive solution to the fine-tuning problem, is discussed next. This solution is only natural if its intrinsic symmetry breaking scale f is relatively close to the electroweak scale. The constraints from the latest results of the 8 TeV run at the LHC are examined. The model's parameter space is being excluded based on a combination of electroweak precision observables, Higgs precision
Quantized Brans Dicke Theory: Phase Transition and Strong Coupling Limit
Pal, Sridip
2016-01-01
We show that Friedmann-Robertson-Walker (FRW) geometry with flat spatial section in quantized (Wheeler deWitt quantization) Brans Dicke (BD) theory reveals a rich phase structure owing to anomalous breaking of a classical symmetry, which maps the scale factor $a\\mapsto\\lambda a$ for some constant $\\lambda$. In the weak coupling ($\\omega$) limit, the theory goes from a symmetry preserving phase to a broken phase. The existence of phase boundary is an obstruction to another classical symmetry [arXiv:gr-qc/9902083] (which relates two BD theory with different coupling) admitted by BD theory with scale invariant matter content i.e $T^{\\mu}{}_{\\mu}=0$. Classically, this prohibits the BD theory to reduce to General Relativity (GR) for scale invariant matter content. We show that strong coupling limit of BD and GR both preserves the symmetry involving scale factor. We also show that with a scale invariant matter content (radiation i.e $P=\\frac{1}{3}\\rho$), the quantized BD theory does reduce to GR as $\\omega\\rightarr...
Strongly coupled quark gluon plasma (SCQGP)
We propose that the reason for the non-ideal behaviour seen in lattice simulation of quark gluon plasma (QGP) and ultrarelativistic heavy ion collision experiments is that the QGP near Tc and above is a strongly coupled plasma (SCP), i.e., a strongly coupled quark gluon plasma (SCQGP). It is remarkable that the widely used equation of state of SCP in QED (quantum electrodynamics) very nicely fits lattice results on all QGP systems, with proper modifications to include colour degrees of freedom and the running coupling constant. Results on pressure in pure gauge, 2-flavours and 3-flavours QGP can all be explained by treating QGP as SCQGP, as demonstrated here. Energy density and speed of sound are also presented for all three systems. We further extend the model to systems with finite quark mass and reasonably good fits to lattice results are obtained for (2+1)-flavours and 4-flavours QGP. Hence it is a unified model, namely SCQGP, to explain the non-ideal QGP seen in lattice simulations with just two system dependent parameters
A strongly coupled Λ-type micromechanical system
Okamoto, Hajime; Schilling, Ryan; Schütz, Hendrik; Sudhir, Vivishek; Wilson, Dalziel J.; Yamaguchi, Hiroshi; Kippenberg, Tobias J.
2016-04-01
We study a classical Λ-type three-level system based on three high-Q micromechanical beam resonators embedded in a gradient electric field. By modulating the strength of the field at the difference frequency between adjacent beam modes, we realize strong dynamic two-mode coupling, via the dielectric force. Driving adjacent pairs simultaneously, we observe the formation of a purely mechanical "dark" state and an all-phononic analog of coherent population trapping—signatures of strong three-mode coupling. The Λ-type micromechanical system is a natural extension of previously demonstrated "two-level" micromechanical systems and adds to the toolbox for engineering of all-phononic micromechanical circuits and arrays.
The Bohm sheath criterion in strongly coupled complex plasmas
A modification of the classical Bohm sheath criterion is investigated in complex plasmas containing Boltzmann electrons, cold fluid ions and strongly coupled microparticles. Equilibrium is provided by an effective 'temperature' associated with electrostatic interactions between charged grains. Using the small-potential expansion approach of the Sagdeev potential, a significant reduction of the ion Bohm velocity is obtained for complex plasma parameters relevant for experiments. The result is of consequence for all problems involving ion drag on microparticles, including parametric instability, structure formation, wave propagation, etc.
Strong coupling of single emitters interacting with phononic infrared antennae
A single emitter can couple with electromagnetic modes of dielectric cavities or metallic particles. In a similar manner, it can couple with a phononic mode supported by a nearby infrared antenna. We consider an emitter with a sufficiently large dipole moment coupled to a SiC bowtie structure supporting strongly localized phononic modes. We show that vacuum Rabi oscillations and large spectral anticrossing are possible, indicating that the emitter–phononic system is in the strong coupling regime. Pure dephasing degrades the response remarkably little. As expected for a quantum but not for a classical formalism, the frequency of the vacuum Rabi oscillations depends on the initial state. We also discuss the possibility of exciting hybrid modes with contributions from the emitter and from more than one of the phononic modes supported by the antenna. Phononic structures appear attractive to study such complex hybridization, as they can support several strongly confined modes with quality factors larger than one hundred in a relatively small spectral window. (paper)
Jet quenching in strongly coupled plasma
Chesler, Paul M
2014-01-01
We present calculations in which an energetic light quark shoots through a finite slab of strongly coupled ${\\cal N}=4$ supersymmetric Yang-Mills (SYM) plasma, with thickness $L$, focussing on what comes out on the other side. We find that even when the "jets" that emerge from the plasma have lost a substantial fraction of their energy they look in almost all respects like "jets" in vacuum with the same reduced energy. The one possible exception is that the opening angle of the "jet" is larger after passage through the slab of plasma than before. Along the way, we obtain a fully geometric characterization of energy loss in the strongly coupled plasma and show that $dE_{\\rm out}/dL \\propto L^2/\\sqrt{x^2_{\\rm stop}-L^2}$, where $E_{\\rm out}$ is the energy of the "jet" that emerges from the slab of plasma and $x_{\\rm stop}$ is the (previously known) stopping distance for the light quark in an infinite volume of plasma.
Classical gravity coupled to Liouville theory
We consider the two dimensional Jackiw-Teitelboim model of gravity. We first couple the model to the Liouville action and c scalar fields and show, treating the combined system as a non linear sigma model, that the resulting theory can be interpreted as a critical string moving in a target space of dimension D = c + 2. We then analyse perturbatively a generalized model containing a kinetic term and an arbitrary potential for the auxiliary field. We use the background field method and work covariant gauges. We show that the renormalizability of the theory depends on the form of the potential. For a general potential, the theory can be renormalized as a non linear sigma model. In the particular case of a Liouville-like potential, the theory is renormalized in the usual sense. (author). 31 refs
Classical gravity coupled to Liouville theory
We consider the two dimensional Jackiw-Teitelboim model of gravity. We first couple the model to the Liouville action and c scalar fields and show, treating the combined system as a non linear sigma model, that the resulting theory can be interpreted as a critical string moving in a target space of dimension D=c+2. We then analyze the model from a perturbative point of view. We show in particular that the results of conformal field theory are exactly reproduced at the one-loop level. We also show that the theory is one loop finite if the cosmological constant Λ is equal to zero. When Λ is different from zero the one loop divergences are gauge-fixing dependent even on-shell. However, the theory can be renormalized as a non linear sigma model if a kinetic term is included for the auxiliary field. (author). 27 refs
Proton radiography of strongly coupled plasma
Complete text of publication follows. Experimental investigations of strongly coupled plasma produced by shock and detonation waves have been conducted at proton radiography facility developed at the ITEP Terawatt Accelerator (TWAC-ITEP). The 800 MeV proton beam intensity in these experiments is about 1010 particles per pulse. A single beam bunch consists of four consequent 70 ns long micro bunches with 250 ns intervals between them. The spatial resolution of the facility that was measured in static experiments is about 50 am. For the generation of shock waves the energy of high explosives (HE) is used, therefore experimental targets are placed within the explosive containment chamber that is certified for the use of up to 100 g of HE in TNT equivalent. The results of latest experiments are presented, including results on propagation of the shock and detonation waves and measurements of the equation of state of strongly coupled shock-induced plasma of argon and xenon. Detonation waves in condensed HE were studied as a dynamic test object at the facility. Series of radiographic images of areal density (i.e. density along the proton beam) of detonating HE charges were obtained in those experiments. On the basis of these images calculations of detonation wave velocities were performed and volume density profiles along the axes of charges were reconstructed. The analysis of these profiles shows that in the vicinity of Chapman - Jouget point, as well as in the following region of unloading, they give not only qualitative but also good quantitative agreement with the known experimental data obtained by other measurement techniques. The experimental investigation of shock-induced strongly coupled plasma of argon and xenon is being conducted at the TWAC-ITEP proton radiography facility now. The shock pressure P in recent argon tests was from 100 to 1000 bars, temperature T was 8-20 kK with non-ideality parameter Γ of about 1. In similar tests with xenon the values of P=4
A True Equation to Couple Classical and Quantum Dynamics
Diosi, Lajos
1995-01-01
Starting from the Schr\\"odinger-equation of a composite system, we derive unified dynamics of a classical harmonic system coupled to an arbitrary quantized system. The classical subsystem is described by random phase-space coordinates entangled with the quantized variables of the complementary subsystem. Our semiclassical equation is {\\it true} in a sense that its predictions are identical to those of the fully quantized composite dynamics. This exact method applies to a broad class of theori...
Strong Local-Nonlocal Coupling for Integrated Fracture Modeling
Littlewood, David John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silling, Stewart A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mitchell, John A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seleson, Pablo D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bond, Stephen D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Parks, Michael L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turner, Daniel Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burnett, Damon J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ostien, Jakob [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Gunzburger, Max [Florida State Univ., Tallahassee, FL (United States)
2015-09-01
Peridynamics, a nonlocal extension of continuum mechanics, is unique in its ability to capture pervasive material failure. Its use in the majority of system-level analyses carried out at Sandia, however, is severely limited, due in large part to computational expense and the challenge posed by the imposition of nonlocal boundary conditions. Combined analyses in which peridynamics is em- ployed only in regions susceptible to material failure are therefore highly desirable, yet available coupling strategies have remained severely limited. This report is a summary of the Laboratory Directed Research and Development (LDRD) project "Strong Local-Nonlocal Coupling for Inte- grated Fracture Modeling," completed within the Computing and Information Sciences (CIS) In- vestment Area at Sandia National Laboratories. A number of challenges inherent to coupling local and nonlocal models are addressed. A primary result is the extension of peridynamics to facilitate a variable nonlocal length scale. This approach, termed the peridynamic partial stress, can greatly reduce the mathematical incompatibility between local and nonlocal equations through reduction of the peridynamic horizon in the vicinity of a model interface. A second result is the formulation of a blending-based coupling approach that may be applied either as the primary coupling strategy, or in combination with the peridynamic partial stress. This blending-based approach is distinct from general blending methods, such as the Arlequin approach, in that it is specific to the coupling of peridynamics and classical continuum mechanics. Facilitating the coupling of peridynamics and classical continuum mechanics has also required innovations aimed directly at peridynamic models. Specifically, the properties of peridynamic constitutive models near domain boundaries and shortcomings in available discretization strategies have been addressed. The results are a class of position-aware peridynamic constitutive laws for
Stochastic properties of strongly coupled plasmas.
Morozov, I V; Norman, G E; Valuev, A A
2001-03-01
Stochastic properties of equilibrium strongly coupled plasmas are investigated by a molecular dynamics method. The Krylov-Kolmogorov entropy K and the dynamical memory time t(m) are calculated both for electrons and ions with mass ratios 10-10(5). Two values of K entropy for ions are discovered corresponding to electron and ion time scales. The dependence of the K entropy on the number of particles, the nonideality parameter, and the form of the interaction potential is investigated. The problem of the accuracy of molecular dynamics simulations is discussed. A universal relation between Kt(m) and the fluctuation of the total energy of the system is obtained. The relation does not depend on the numerical integration scheme, temperature, density, and the interparticle interaction potential, so that it may be applied to arbitrary dynamic systems. Transition from dynamic to stochastic correlation is treated for both electron and ion velocity autocorrelation functions, for Langmuir and ion-sound plasma wave dynamic structure factors. We point to quantum uncertainty as a physical reason which limits dynamic (Newton) correlation for times greater than t(m). PMID:11308773
Strongly coupled dusty plasmas: crystals, liquids, clusters and waves
The dusty plasma is a system that consists of many strongly-charged fine dust particles suspended in a plasma background. The slow dynamics and strong coupling due to the large mass and charges lead to the formation of highly-ordered dust crystal structures suspended in the plasma background, which can be directly observed. The dusty plasma forms a link to the area of condensed matter physics for the study of many interesting microscopic phenomena from order to disorder. In this paper, we introduce the special properties of this system from the viewpoint of conventional plasma physics, then we briefly review past works on the structure and dynamical behaviour from the highly-ordered state, through the melting and liquid states with associated vortex-type excitation and anomalous diffusion, to the state with self-organized macroscopic dust waves after losing microscopic order. The first observation of strongly-coupled dust Coulomb clusters with small numbers of particles from a few to a few hundred, which resemble classical atoms, is also demonstrated. (author)
Classical and quantum models of strong cosmic censorship
The cosmic censorship conjecture states that naked singularities should not evolve from regular initial conditions in general relativity. In its strong form the conjecture asserts that space-times with Cauchy horizons must always be unstable and thus that the generic solution of Einstein's equations must be inextendible beyond its maximal Cauchy development. In this paper it is shown that one can construct an infinite-dimensional family of extendible cosmological solutions similar to Taub-NUT space-time; however, each of these solutions is unstable in precisely the way demanded by strong cosmic censorship. Finally it is shown that quantum fluctuations in the metric always provide (though in an unexpectedly subtle way) the ''generic perturbations'' which destroy the Cauchy horizons in these models. (author)
Damped driven coupled oscillators: entanglement, decoherence and the classical limit
Mancilla, R D Guerrero; Rey-Gonzalez, R R; Fonseca-Romero, K M [Grupo de Optica e Informacion Cuantica, Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia)], E-mail: rdguerrerom@unal.edu.co, E-mail: rrreyg@unal.edu.co, E-mail: kmfonsecar@unal.edu.co
2009-03-13
We investigate the quantum-classical border, the entanglement and decoherence of an analytically solvable model, comprising a first subsystem (a harmonic oscillator) coupled to a driven and damped second subsystem (another harmonic oscillator). We choose initial states whose dynamics is confined to a couple of two-level systems, and show that the maximum value of entanglement between the two subsystems, as measured by concurrence, depends on the dissipation rate to the coupling-constant ratio and the initial state. While in a related model the entropy of the first subsystem (a two-level system) never grows appreciably (for large dissipation rates), in our model it reaches a maximum before decreasing. Although both models predict small values of entanglement and dissipation, for fixed times of the order of the inverse of the coupling constant and large dissipation rates, these quantities decrease faster, as a function of the ratio of the dissipation rate to the coupling constant, in our model.
Ultrafast polariton-phonon dynamics of strongly coupled quantum dot-nanocavity systems
Müller, Kai; Fischer, Kevin A.; Rundquist, Armand; Dory, Constantin; Lagoudakis, Konstantinos G.; Sarmiento, Tomas; Kelaita, Yousif A.; Borish, Victoria; Vučković, Jelena
2015-01-01
We investigate the influence of exciton-phonon coupling on the dynamics of a strongly coupled quantum dot-photonic crystal cavity system and explore the effects of this interaction on different schemes for non-classical light generation. By performing time-resolved measurements, we map out the detuning-dependent polariton lifetime and extract the spectrum of the polariton-to-phonon coupling with unprecedented precision. Photon-blockade experiments for different pulse-length and detuning condi...
Time-dependent coupled harmonic oscillators: classical and quantum solutions
In this work we present the classical and quantum solutions for an arbitrary system of time-dependent coupled harmonic oscillators, where the masses (m), frequencies (ω) and coupling parameter (k) are functions of time. To obtain the classical solutions, we use a coordinate and momentum transformations along with a canonical transformation to write the original Hamiltonian as the sum of two Hamiltonians of uncoupled harmonic oscillators with modified time-dependent frequencies and unitary masses. To obtain the exact quantum solutions we use a unitary transformation and the Lewis and Riesenfeld (LR) invariant method. The exact wave functions are obtained by solving the respective Milne–Pinney (MP) equation for each system. We obtain the solutions for the system with m1 = m2 = m0eγt, ω1 = ω01e-γt/2, ω2 = ω02e-γt/2 and k = k0. (author)
Supersymmetric QCD: Exact Results and Strong Coupling
Dine, Michael; Pack, Lawrence; Park, Chang-Soon; Ubaldi, Lorenzo; Wu, Weitao
2011-01-01
We revisit two longstanding puzzles in supersymmetric gauge theories. The first concerns the question of the holomorphy of the coupling, and related to this the possible definition of an exact (NSVZ) beta function. The second concerns instantons in pure gluodynamics, which appear to give sensible, exact results for certain correlation functions, which nonetheless differ from those obtained using systematic weak coupling expansions. For the first question, we extend an earlier proposal of Arkani-Hamed and Murayama, showing that if their regulated action is written suitably, the holomorphy of the couplings is manifest, and it is easy to determine the renormalization scheme for which the NSVZ formula holds. This scheme, however, is seen to be one of an infinite class of schemes, each leading to an exact beta function; the NSVZ scheme, while simple, is not selected by any compelling physical consideration. For the second question, we explain why the instanton computation in the pure supersymmetric gauge theory is...
On the Heterotic Dipole at Strong Coupling
Mukherji, Sudipta
1999-01-01
We analyse the dipole solution of heterotic string theory in four dimensions. It has the structure of monopole and anti-monopole connected by flux line (string). Due to growing coupling near the poles, the length of the string diverges. However, exploiting the self-duality of heterotic string theory in four dimension, we argue that this string is correctly described in terms of dual variables.
Fluorescence measurements of expanding strongly-coupled neutral plasmas
Cummings, E A; Durfee, D S; Bergeson, S D
2005-01-01
We report new detailed density profile measurements in expanding strongly-coupled neutral plasmas. Using laser-induced fluorescence techniques, we determine plasma densities in the range of 10^5 to 10^9/cm^3 with a time resolution limit as small as 7 ns. Strong-coupling in the plasma ions is inferred directly from the fluorescence signals. Evidence for strong-coupling at late times is presented, confirming a recent theoretical result.
The gauge structure of strong coupling gravity
In the limit of infinite Newton constant the 1+d dimensional Einstein–Hilbert action reduces to that of a SL(d,R)/SO(d)×R+ nonlinear sigma-model where spatial points are coupled merely by shift terms giving rise to a diffeomorphism constraint. The full group of 1+d diffeomorphisms is shown to act non-tensorially as a gauge group on the action and the field equations. This is used to establish the admissibility as a gauge condition of the combined constant mean curvature (CMC) and zero shift conditions for spatially closed hypersurfaces. This ‘CMC gauge’ eventually allows for a concise isolation of the gauge invariant and physical degrees of freedoms. Here we utilize the CMC gauge to obtain a complete set of dynamical fields which are invariant under all gauge transformations but time independent spatial diffeomorphisms. (paper)
A strongly coupled zig-zag transition
Balasubramanian, Vijay; Ross, Simon F; Simon, Joan
2013-01-01
The zig-zag symmetry transition is a phase transition in 1D quantum wires, in which a Wigner lattice of electrons transitions to two staggered lattices. Previous studies model this transition as a Luttinger liquid coupled to a Majorana fermion. The model exhibits interesting RG flows, involving quenching of velocities in subsectors of the theory. We suggest an extension of the model which replaces the Majorana fermion by a more general CFT; this includes an experimentally realizable case with two Majorana fermions. We analyse the RG flow both in field theory and using AdS/CFT techniques in the large central charge limit of the CFT. The model has a rich phase structure with new qualitative features, already in the two Majorana fermion case. The AdS/CFT calculation involves considering back reaction in space-time to capture subleading effects.
Classical nuclear motion coupled to electronic non-adiabatic transitions
Agostini, Federica; Gross, E K U
2014-01-01
We present a detailed derivation and numerical tests of a new mixed quantum-classical scheme to deal with non-adiabatic processes. The method is presented as the zero-th order approximation to the exact coupled dynamics of electrons and nuclei offered by the factorization of the electron-nuclear wave function [A. Abedi, N. T. Maitra and E. K. U. Gross, Phys. Rev. Lett., 105 (2010)]. Numerical results are presented for a model system for non-adiabatic charge transfer in order to test the performance of the method and to validate the underlying approximations.
Integrable Couplings of Classical-Boussinesq Hierarchy and Its Hamiltonian Structure
By using a Lie algebra, an integrable couplings of the classical-Boussinesq hierarchy is obtained. Then, the Hamiltonian structure of the integrable couplings of the classical-Boussinesq is obtained by the quadratic-form identity. (general)
Infrared Limit of Gluon Amplitudes at Strong Coupling
Buchbinder, Evgeny I.
2007-01-01
In this note, we propose that the infrared structure of gluon amplitudes at strong coupling can be fully extracted from a local consideration near cusps. This is consistent with field theory and correctly reproduces the infrared divergences of the four-gluon amplitude at strong coupling calculated recently by Alday and Maldacena.
Strong Couplings of Three Mesons with Charm(ing) Involvement
Lucha, Wolfgang; Sazdjian, Hagop; Simula, Silvano
2016-01-01
We determine the strong couplings of three mesons that involve, at least, one $\\eta_c$ or $J/\\psi$ meson, within the framework of a constituent-quark model by means of relativistic dispersion formulations. For strong couplings of $J/\\psi$ mesons to two charmed mesons, our approach leads to predictions roughly twice as large as those arising from QCD sum rules.
Shear viscosities of photons in strongly coupled plasmas
Yang, Di-Lun; Müller, Berndt
2016-09-01
We investigate the shear viscosity of thermalized photons in the quark gluon plasma (QGP) at weak coupling and N = 4 super Yang-Mills plasma (SYMP) at both strong and weak couplings. We find that the shear viscosity due to the photon-parton scattering up to the leading order of electromagnetic coupling is suppressed when the coupling of the QGP/SYMP is increased, which stems from the blue-shift of the thermal-photon spectrum at strong coupling. In addition, the shear viscosity rapidly increases near the deconfinement transition in a phenomenological model analogous to the QGP.
Resurgence and Holomorphy: From Weak to Strong Coupling
Cherman, Aleksey; Ünsal, Mithat
2014-01-01
We analyze the resurgence properties of finite-dimensional exponential integrals which are prototypes for partition functions in quantum field theories. In these simple examples, we demonstrate that perturbation theory, even at arbitrarily weak coupling, fails as the argument of the coupling constant is varied. It is well-known that perturbation theory also fails at stronger coupling. We show that these two failures are actually intimately related. The formalism of resurgent transseries, which takes into account global analytic continuation properties, fixes both problems, and provides an arbitrarily accurate description of exact result for any value of coupling. This means that strong coupling results can be deduced by using merely weak coupling data. Finally, we give another perspective on resurgence theory by showing that the monodromy properties of the weak coupling results are in precise agreement with the monodromy properties of the strong-coupling expansions, obtained using analysis of the holomorphy s...
Resurgence and holomorphy: From weak to strong coupling
Cherman, Aleksey, E-mail: acherman@umn.edu [Fine Theoretical Physics Institute, Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Koroteev, Peter, E-mail: pkoroteev@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L2Y5 (Canada); Ünsal, Mithat, E-mail: unsal.mithat@gmail.com [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States)
2015-05-15
We analyze the resurgence properties of finite-dimensional exponential integrals which are prototypes for partition functions in quantum field theories. In these simple examples, we demonstrate that perturbation theory, even at arbitrarily weak coupling, fails as the argument of the coupling constant is varied. It is well-known that perturbation theory also fails at stronger coupling. We show that these two failures are actually intimately related. The formalism of resurgent transseries, which takes into account global analytic continuation properties, fixes both problems and provides an arbitrarily accurate description of exact result for any value of coupling. This means that strong coupling results can be deduced by using merely weak coupling data. Finally, we give another perspective on resurgence theory by showing that the monodromy properties of the weak coupling results are in precise agreement with the monodromy properties of the strong-coupling expansions, obtained using analysis of the holomorphy structure of Picard-Fuchs equations.
Critical and strong-coupling phases in one- and two-bath spin-boson models.
Guo, Cheng; Weichselbaum, Andreas; von Delft, Jan; Vojta, Matthias
2012-04-20
For phase transitions in dissipative quantum impurity models, the existence of a quantum-to-classical correspondence has been discussed extensively. We introduce a variational matrix product state approach involving an optimized boson basis, rendering possible high-accuracy numerical studies across the entire phase diagram. For the sub-Ohmic spin-boson model with a power-law bath spectrum ∝ω(s), we confirm classical mean-field behavior for s<1/2, correcting earlier numerical renormalization-group results. We also provide the first results for an XY-symmetric model of a spin coupled to two competing bosonic baths, where we find a rich phase diagram, including both critical and strong-coupling phases for s<1, different from that of classical spin chains. This illustrates that symmetries are decisive for whether or not a quantum-to-classical correspondence exists. PMID:22680701
Classical trajectory perspective of atomic ionization in strong laser fields semiclassical modeling
Liu, Jie
2014-01-01
The ionization of atoms and molecules in strong laser fields is an active field in modern physics and has versatile applications in such as attosecond physics, X-ray generation, inertial confined fusion (ICF), medical science and so on. Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields covers the basic concepts in this field and discusses many interesting topics using the semiclassical model of classical trajectory ensemble simulation, which is one of the most successful ionization models and has the advantages of a clear picture, feasible computing and accounting for many exquisite experiments quantitatively. The book also presents many applications of the model in such topics as the single ionization, double ionization, neutral atom acceleration and other timely issues in strong field physics, and delivers useful messages to readers with presenting the classical trajectory perspective on the strong field atomic ionization. The book is intended for graduate students and researchers...
Fluctuation effects on QCD phase diagram at strong coupling
Ichihara, Terukazu
2015-01-01
We study the QCD phase diagram away from the strong coupling limit (SCL) with fluctuation effects in the auxiliary field Monte-Carlo (AFMC) method. First, we give an effective action which contains next-to-leading order (NLO) finite coupling effects of the strong coupling expansion as well as fluctuation effects. Second, we examine NLO effects of the strong coupling expansion in AFMC at zero quark density. We find that the chiral condensate is reduced by both NLO terms from temporal plaquettes and fluctuation effects, and almost no dependence on NLO terms from spatial plaquettes in the current analysis. These behaviors can be understood from the modification of the mass and the wave function renormalization factor by auxiliary fields as in the mean field analysis and the fluctuation effects in the strong coupling limit.
On the strong coupling scale in Higgs G-inflation
Higgs G-inflation is an inflation model that takes advantage of a Galileon-like derivative coupling. It is a non-renormalizable operator and is strongly coupled at high energy scales. Perturbative analysis does not have a predictive power any longer there. In general, when the Lagrangian is expanded around the vacuum, the strong coupling scale is identified as the mass scale that appears in non-renormalizable operators. In inflationary models, however, the identification of the strong coupling scale is subtle, since the structures of the kinetic term as well as the interaction itself can be modified by the background inflationary dynamics. Therefore, the strong coupling scale depends on the background. In this letter, we evaluate the strong coupling scale of the fluctuations around the background in the Higgs G-inflation including the Nambu–Goldstone modes associated with the symmetry breaking. We find that the system is sufficiently weakly coupled when the scales which we now observe exit the horizon during inflation and the observational predictions with the semiclassical treatment are valid. However, we also find that the inflaton field value at which the strong coupling scale and the Hubble scale meet is less than the Planck scale. Therefore, we cannot describe the model from the Planck scale, or the chaotic initial condition
On the strong coupling scale in Higgs G-inflation
Kamada, Kohei, E-mail: kohei.kamada@epfl.ch
2015-05-11
Higgs G-inflation is an inflation model that takes advantage of a Galileon-like derivative coupling. It is a non-renormalizable operator and is strongly coupled at high energy scales. Perturbative analysis does not have a predictive power any longer there. In general, when the Lagrangian is expanded around the vacuum, the strong coupling scale is identified as the mass scale that appears in non-renormalizable operators. In inflationary models, however, the identification of the strong coupling scale is subtle, since the structures of the kinetic term as well as the interaction itself can be modified by the background inflationary dynamics. Therefore, the strong coupling scale depends on the background. In this letter, we evaluate the strong coupling scale of the fluctuations around the background in the Higgs G-inflation including the Nambu–Goldstone modes associated with the symmetry breaking. We find that the system is sufficiently weakly coupled when the scales which we now observe exit the horizon during inflation and the observational predictions with the semiclassical treatment are valid. However, we also find that the inflaton field value at which the strong coupling scale and the Hubble scale meet is less than the Planck scale. Therefore, we cannot describe the model from the Planck scale, or the chaotic initial condition.
On the strong coupling scale in Higgs G-inflation
Kohei Kamada
2015-05-01
Full Text Available Higgs G-inflation is an inflation model that takes advantage of a Galileon-like derivative coupling. It is a non-renormalizable operator and is strongly coupled at high energy scales. Perturbative analysis does not have a predictive power any longer there. In general, when the Lagrangian is expanded around the vacuum, the strong coupling scale is identified as the mass scale that appears in non-renormalizable operators. In inflationary models, however, the identification of the strong coupling scale is subtle, since the structures of the kinetic term as well as the interaction itself can be modified by the background inflationary dynamics. Therefore, the strong coupling scale depends on the background. In this letter, we evaluate the strong coupling scale of the fluctuations around the background in the Higgs G-inflation including the Nambu–Goldstone modes associated with the symmetry breaking. We find that the system is sufficiently weakly coupled when the scales which we now observe exit the horizon during inflation and the observational predictions with the semiclassical treatment are valid. However, we also find that the inflaton field value at which the strong coupling scale and the Hubble scale meet is less than the Planck scale. Therefore, we cannot describe the model from the Planck scale, or the chaotic initial condition.
Classical trajectory perspective of atomic ionization in strong laser fields. Semiclassical modeling
Dealing with timely and interesting issues in strong laser physics. Illustrates complex strong field atomic ionization with the simple semiclassical model of classical trajectory perspective for the first time. Provides a theoretical model that can be used to account for recent experiments. The ionization of atoms and molecules in strong laser fields is an active field in modern physics and has versatile applications in such as attosecond physics, X-ray generation, inertial confined fusion (ICF), medical science and so on. Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields covers the basic concepts in this field and discusses many interesting topics using the semiclassical model of classical trajectory ensemble simulation, which is one of the most successful ionization models and has the advantages of a clear picture, feasible computing and accounting for many exquisite experiments quantitatively. The book also presents many applications of the model in such topics as the single ionization, double ionization, neutral atom acceleration and other timely issues in strong field physics, and delivers useful messages to readers with presenting the classical trajectory perspective on the strong field atomic ionization. The book is intended for graduate students and researchers in the field of laser physics, atom molecule physics and theoretical physics. Dr. Jie Liu is a professor of Institute of Applied Physics and Computational Mathematics, China and Peking University.
One-link integral in the lattice QCD: Strong coupling
We review different calculation methods of the one-link integral, appearing in the strong coupling approximation in the lattice QCD. Some new formulae useful in the case of lattice QCD with Susskind fermions are also presented. (orig.)
One-link integral in the lattice QCD: Strong coupling
Azakov, S.I.; Aliev, E.S.
1988-12-01
We review different calculation methods of the one-link integral, appearing in the strong coupling approximation in the lattice QCD. Some new formulae useful in the case of lattice QCD with Susskind fermions are also presented.
One-link integral in the lattice QCD: Strong coupling
We review different calculation methods of the one-link integral, appearing in the strong coupling approximation in the lattice QCD. Some new formulae useful in the case of lattice QCD with Susskind fermions are also presented. (author). 18 refs
Non-linear coupling of quantum theory and classical gravity
The possibility that the non-linear evolution proposed earlier for a relativistic quantum field theory may be related to its coupling to a classical gravitational field is discussed. Formally, in the Schroedinger picture, it is shown how both the Schroedinger equation and Einstein's equations (with the expectation value of the energy-momentum tensor on the right) can be derived from a variational principle. This yields a non-linear quantum evolution. Other terms can be added to the action integral to incorporate explicit non-linearities of the type discussed previously. The possibility of giving a meaning to the resulting equation in a Heisenberg or interaction-like picture, is briefly discussed. (author)
Parametric strong mode-coupling in carbon nanotube mechanical resonators
Li, Shu-Xiao; Zhu, Dong; Wang, Xin-He; Wang, Jiang-Tao; Deng, Guang-Wei; Li, Hai-Ou; Cao, Gang; Xiao, Ming; Guo, Guang-Can; Jiang, Kai-Li; Dai, Xing-Can; Guo, Guo-Ping
2016-08-01
Carbon nanotubes (CNTs) have attracted much attention for use in nanomechanical devices because of their exceptional properties, such as large resonant frequencies, low mass, and high quality factors. Here, we report the first experimental realization of parametric strong coupling between two mechanical modes on a single CNT nanomechanical resonator, by applying an extra microwave pump. This parametric pump method can be used to couple mechanical modes with arbitrary frequency differences. The properties of the mechanical resonator are detected by single-electron tunneling at low temperature, which is found to be strongly coupled to both modes. The coupling strength between the two modes can be tuned by the pump power, setting the coupling regime from weak to strong. This tunability may be useful in further phonon manipulations in carbon nanotubes.Carbon nanotubes (CNTs) have attracted much attention for use in nanomechanical devices because of their exceptional properties, such as large resonant frequencies, low mass, and high quality factors. Here, we report the first experimental realization of parametric strong coupling between two mechanical modes on a single CNT nanomechanical resonator, by applying an extra microwave pump. This parametric pump method can be used to couple mechanical modes with arbitrary frequency differences. The properties of the mechanical resonator are detected by single-electron tunneling at low temperature, which is found to be strongly coupled to both modes. The coupling strength between the two modes can be tuned by the pump power, setting the coupling regime from weak to strong. This tunability may be useful in further phonon manipulations in carbon nanotubes. Electronic supplementary information (ESI) available: Fit of the quality factor and similar results in more devices. See DOI: 10.1039/c6nr02853e
Jet quenching within a hybrid strong/weak coupling approach
We propose a novel hybrid model for jet quenching, including both strong and weak coupling physics where each seems appropriate. Branching in the parton shower is assumed to be perturbative and described by DGLAP evolution, while interactions with the medium result in each parton in the shower losing energy as at strong coupling, as realized holographically. The medium-modified parton shower is embedded into a hydrodynamic evolution of hot QCD plasma and confronted with LHC jet data
Strong coupling between surface plasmon polaritons and emitters
Törmä, P.; Barnes, W.L.
2014-01-01
In this review we look at the concepts and state-of-the-art concerning the strong coupling of surface plasmon-polariton modes to states associated with quantum emitters such as excitons in J-aggregates, dye molecules and quantum dots. We explore the phenomenon of strong coupling with reference to a number of examples involving electromagnetic fields and matter. We then provide a concise description of the relevant background physics of surface plasmon polaritons. An extensive overview of the ...
Strongly Coupled Models with a Higgs-like Boson
Pich Antonio; Rosell Ignasi; Sanz-Cillero Juan José
2013-01-01
Considering the one-loop calculation of the oblique S and T parameters, we have presented a study of the viability of strongly-coupled scenarios of electroweak symmetry breaking with a light Higgs-like boson. The calculation has been done by using an effective Lagrangian, being short-distance constraints and dispersive relations the main ingredients of the estimation. Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models with massive resonances are...
Instability of Longitudinal Wave in Magnetized Strongly Coupled Dusty Plasma
谢柏松
2003-01-01
Instability of longitudinal wave in magnetized strongly coupled dusty plasmas is investigated. The dust charging relaxation is taken into account. It is found that there exists threshold of interdust distance for the instability of wave, which is determined significantly by the dust charging relaxation, the coupling parameter of high correlation of dust as well the strength of magnetic field.
Experimental determination of the effective strong coupling constant
Alexandre Deur; Volker Burkert; Jian-Ping Chen; Wolfgang Korsch
2005-09-15
We extract an effective strong coupling constant from low Q2 data on the Bjorken sum. Using sum rules, we establish its Q2-behavior over the complete Q2-range. The result is compared to effective coupling constants extracted from different processes and to calculations based on Schwinger-Dyson equations, hadron spectroscopy or lattice QCD. Although the connection between the experimentally extracted effective coupling constant and the calculations is not clear, the results agree surprisingly well.
Single particle motion in the strongly coupled one-component plasma in a uniform magnetic filed
The sustained interest in the strongly coupled one component classical plasma (OCP) over the several years have yielded much insight into its static and dynamical properties. However until the recent molecular dynamics (MD) simulation of Bernu, little was known about the effects of an external magnetic field on the dynamical properties of the strongly coupled OCP in three dimensions. Since, Bernu's results for the velocity autocorrelation functions and the self-diffusion coefficients are not well understood, it is proposed to develop more sophisticated theoretical models for single particle motion in the OCP with an applied magnetic field. (author)
Real-time quantum trajectories for classically allowed dynamics in strong laser fields
Plimak, L I
2015-01-01
Both the physical picture of the dynamics of atoms and molecules in intense infrared fields and its theoretical description use the concept of electron trajectories. Here we address a key question which arises in this context: Are distinctly quantum features of these trajectories, such as the complex-valued coordinates, physically relevant in the classically allowed region of phase space, and what is their origin? First, we argue that solutions of classical equations of motion can account for quantum effects. To this end, we construct an exact solution to the classical Hamilton-Jacobi equation which accounts for dynamics of the wave packet, and show that this solution is physically correct in the limit $\\hbar \\to 0$. Second, we show that imaginary components of classical trajectories are directly linked to the finite size of the initial wavepacket in momentum space. This way, if the electronic wavepacket produced by optical tunneling in strong infrared fiels is localised both in coordinate and momentum, its m...
Driven transverse shear waves in a strongly coupled dusty plasma
Bandyopadhyay, P. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)], E-mail: banerjee_pintu2002@yahoo.com; Prasad, G.; Sen, A.; Kaw, P.K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2008-08-11
The linear dispersion properties of transverse shear waves in a strongly coupled dusty plasma are experimentally studied in a DC discharge device by exciting them in a controlled manner with a variable frequency external source. The dusty plasma is maintained in the strongly coupled fluid regime with (1<{gamma}<<{gamma}{sub c}) where {gamma} is the Coulomb coupling parameter and {gamma}{sub c} is the crystallization limit. A dispersion relation for the transverse waves is experimentally obtained over a frequency range of 0.1 Hz to 2 Hz and found to show good agreement with viscoelastic theoretical results.
Strong Single-Photon Coupling in Superconducting Quantum Magnetomechanics
Via, Guillem; Kirchmair, Gerhard; Romero-Isart, Oriol
2015-04-01
We show that the inductive coupling between the quantum mechanical motion of a superconducting microcantilever and a flux-dependent microwave quantum circuit can attain the strong single-photon nanomechanical coupling regime with feasible experimental parameters. We propose to use a superconducting strip, which is in the Meissner state, at the tip of a cantilever. A pickup coil collects the flux generated by the sheet currents induced by an external quadrupole magnetic field centered at the strip location. The position-dependent magnetic response of the superconducting strip, enhanced by both diamagnetism and demagnetizing effects, leads to a strong magnetomechanical coupling to quantum circuits.
Dynamic compression of strongly coupled plasmas at megabars
Complete text of publication follows. New experimental results on thermodynamics and electrical conductivity of shock and isoentropically compressed hydrogen and deuterium are presented. Strongly coupled plasmas at pressures achieved 18 Mbar, Coulomb coupling parameter exceeded 450, electron degeneracy parameter came up to 290 were obtained with semi-spherical explosive-driven generators. Theoretical models for description of thermodynamics of strongly coupled hydrogen are discussed, comparison of the experimental and theoretical data for strongly non-ideal hydrogen plasmas under high energy density are presented. Experimental and theoretical problems in studying of warm dense hydrogen are discussed. Problems of accurate description of weakly coupled solar plasma on basis of astrophysical observations are discussed as well.
Dust acoustic instability in a strongly coupled dusty plasma
Rosenberg, M.; Kalman, G. J.; Hartmann, P.; Goree, J.
2013-10-01
Dusty plasmas are plasmas containing charged micron to sub-micron size dust grains (solid particulates). Because the grains can be multiply charged and are much more massive than the ions, the presence of dust can lead to novel waves such as the dust acoustic wave, which is a compressional wave that can be excited by a flow of ions that is driven by an electric field. Moreover, the large dust charge can result in strong Coulomb coupling between the dust grains, where the electrostatic energy between neighboring grains is larger than their thermal (kinetic) energy. When the coupling between dust grains is strong, but not large enough for crystallization, the dust is in the strongly coupled liquid phase. This poster theoretically investigates the dust acoustic instability, which is driven by sub-thermal ion flow, in a three-dimensional dusty plasma in the strongly coupled liquid phase. It is found that strong coupling enhances the instability. The application is to microgravity experiments with dusty plasma planned for the PK-4 and PlasmaLab instruments, which are in development for the International Space Station. Microgravity conditions enable the preparation of dust clouds under these sub-thermal ion flow conditions by avoiding the need for strong electric fields to levitate the dust grains.
Suzuki, Yasumitsu; Watanabe, Kazuyuki; Abedi, Ali; Agostini, Federica; Min, Seung Kyu; Maitra, Neepa; Gross, E. K. U.
The exact factorization of the electron-nuclear wave function allows to define the time-dependent potential energy surfaces (TDPESs) responsible for the nuclear dynamics and electron dynamics. Recently a novel coupled-trajectory mixed quantum-classical (CT-MQC) approach based on this TDPES has been developed, which accurately reproduces both nuclear and electron dynamics. Here we study the TDPES for laser-induced electron localization with a view to developing a MQC method for strong-field processes. We show our recent progress in applying the CT-MQC approach to the systems with many degrees of freedom.
Momentum transport in strongly coupled anisotropic plasmas in the presence of strong magnetic fields
Finazzo, Stefano Ivo; Rougemont, Romulo; Noronha, Jorge
2016-01-01
We present a holographic perspective on momentum transport in strongly coupled, anisotropic non-Abelian plasmas in the presence of strong magnetic fields. We compute the anisotropic heavy quark drag forces and Langevin diffusion coefficients and also the anisotropic shear viscosities for two different holographic models, namely, a top-down deformation of strongly coupled $\\mathcal{N} = 4$ Super-Yang-Mills (SYM) theory triggered by an external Abelian magnetic field, and a bottom-up Einstein-Maxwell-dilaton (EMD) model which is able to provide a quantitative description of lattice QCD thermodynamics with $(2+1)$-flavors at both zero and nonzero magnetic fields. We find that, in general, energy loss and momentum diffusion through strongly coupled anisotropic plasmas are enhanced by a magnetic field being larger in transverse directions than in the direction parallel to the magnetic field. Moreover, the anisotropic shear viscosity coefficient is smaller in the direction of the magnetic field than in the plane pe...
Slepyan, G. Ya.; Yerchak, Y. D.; Maksimenko, S. A.; Hoffmann, A
2008-01-01
Interaction of traveling wave of classic light with 1D-chain of coupled quantum dots (QDs) in strong coupling regime has been theoretically considered. The effect of space propagation of Rabi oscillations in the form of traveling waves and wave packets has been predicted. Physical interpretation of the effect has been given, principles of its experimental observation are discussed.
A Hybrid Strong/Weak Coupling Approach to Jet Quenching
Casalderrey-Solana, Jorge; Milhano, José Guilherme; Pablos, Daniel; Rajagopal, Krishna
2014-01-01
We propose and explore a new hybrid approach to jet quenching in a strongly coupled medium. The basis of this phenomenological approach is to treat physics processes at different energy scales differently. The high-$Q^2$ processes associated with the QCD evolution of the jet from production as a single hard parton through its fragmentation, up to but not including hadronization, are treated perturbatively. The interactions between the partons in the shower and the deconfined matter within which they find themselves lead to energy loss. The momentum scales associated with the medium (of the order of the temperature) and with typical interactions between partons in the shower and the medium are sufficiently soft that strongly coupled physics plays an important role in energy loss. We model these interactions using qualitative insights from holographic calculations of the energy loss of energetic light quarks and gluons in a strongly coupled plasma, obtained via gauge/gravity duality. We embed this hybrid model ...
Hydrodynamic transport in strongly coupled disordered quantum field theories
Lucas, Andrew
2015-01-01
We compute direct current (dc) thermoelectric transport coefficients in strongly coupled quantum field theories without long lived quasiparticles, at finite temperature and charge density, and disordered on long wavelengths compared to the length scale of local thermalization. Many previous transport computations in strongly coupled systems are interpretable hydrodynamically, despite formally going beyond the hydrodynamic regime. This includes momentum relaxation times previously derived by the memory matrix formalism, and non-perturbative holographic results; in the latter case, this is subject to some important subtleties. Our formalism may extend some memory matrix computations to higher orders in the perturbative disorder strength, as well as give valuable insight into non-perturbative regimes. Strongly coupled metals with quantum critical contributions to transport generically transition between coherent and incoherent metals as disorder strength is increased at fixed temperature, analogous to mean field...
Two and three-point correlators of operators dual to folded string solutions at strong coupling
Georgiou, George
2010-01-01
A particular analytic continuation of classical string solutions having a single AdS_5 spin is considered. These solutions describe strings tunnelling from the boundary to the boundary of AdS_5. We use the Legendre transform of the dimensionally regularised action of these solutions to evaluate the 2-point functions of the dual operators, holographically. Subsequently, we evaluate the structure coefficient of correlators involving two operators with spin S and a BPS state, at strong coupling....
Very strong coupling in GaAs based optical microcavities
Zhang, H.; Kim, N.Y.; Yamamoto, Y.; Na, N.
2012-01-01
We show that when following a simple cavity design metric, a quantum well exciton-microcavity photon coupling constant can be larger than the exciton binding energy in GaAs based optical microcavities. Such a very strong coupling significantly reduces the relative electron-hole motion and makes the polaritons robust against phonon collisions. The corresponding polariton dissociation and saturation boundaries on the phase diagram are much improved, and our calculations suggest the possibility ...
Polyakov Loops in Strongly-Coupled Plasmas with Gravity Duals
Noronha, Jorge
2010-01-01
We study the properties of the Polyakov loop in strongly-coupled gauge plasmas that are conjectured to be dual to five dimensional theories of gravity coupled to a nontrivial single scalar field. We find a gravity dual that can describe the thermodynamic properties and also the expectation value of the Polyakov loop in the deconfined phase of quenched SU(3) QCD up to $3T_c$.
Improving entanglement of two atoms in strong coupling regime
Liu, Hui; Yang, Qing; Yang, Ming; Cao, Zhuoliang
2016-03-01
We consider a model of two identical atoms coupled to a single-mode cavity. When in atom-field strong coupling regime, the entanglement of the two atoms with spontaneous emission should be investigated beyond rotating-wave approximation (RWA). In order to improve the entanglement of the two atoms, some typical feedback based on quantum-jump are attempted to impose on the atoms. The result of numerical simulations shows that an appropriate feedback control can improve the entanglement.
Automatic differentiation based solution of strongly coupled problems in engineering
Hudobivnik, Blaž
2016-01-01
The doctoral thesis presents an approach for the formulation and solution of strongly coupled engineering problems with the finite element method using the automatic differentiation technique that the software tools AceGen and AceFEM enables. It has been shown that it is possible to transform arbitrarily weak form of differential equation of coupled problems into scalar function pseudo-potential. By using the automatic differentiation and appropriate exceptions in the differentiation pr...
Raman scattering with strongly coupled vibron-polaritons
Strashko, Artem
2016-01-01
Strong coupling between cavity photons and molecular vibrations can lead to the formation of vibron-polaritons. In a recent experiment with PVAc molecules in a metal-metal microcavity [A.Shalabney et al., Ang.Chem.Int.Ed. 54 7971 (2015)], such a coupling was observed to enhance the Raman scattering probability by several orders of magnitude. Inspired by this, we theoretically analyze the effect of strong photon-vibron coupling on the Raman scattering amplitude of organic molecules. This problem has recently been addressed in [J.del Pino, J.Feist and F.J.Garcia-Vidal; J.Phys.Chem.C 119 29132 (2015)] using exact numerics for a small number of molecules. In this paper we derive compact analytic results for any number of molecules, also including the ultra-strong coupling regime. Our calculations predict a division of the Raman signal into upper and lower polariton modes,with some enhancement to the lower polariton Raman amplitude due to the mode softening under strong coupling.
Hamilton-Jacobi solutions for strongly coupled gravity and matter
Salopek, D. S.
1998-05-01
A Green function method is developed for solving strongly coupled gravity and matter in the semiclassical limit. In the strong-coupling limit, one assumes that Newton's constant approaches infinity, 0264-9381/15/5/009/img1. As a result, one may neglect second-order spatial gradients, and each spatial point evolves like a homogeneous universe. After constructing the Green function solution to the Hamiltonian constraint, the momentum constraint is solved using functional methods in conjunction with the superposition principle for Hamilton-Jacobi theory. Exact and approximate solutions are given for a dust field or a scalar field interacting with gravity.
On the collinear limit of scattering amplitudes at strong coupling
Basso, Benjamin; Vieira, Pedro
2015-01-01
In this letter we consider the collinear limit of gluon scattering amplitudes in planar N=4 SYM theory at strong coupling. We argue that in this limit scattering amplitudes map into correlators of twist fields in the two dimensional non-linear O(6) sigma model, similar to those appearing in recent studies of entanglement entropy. We provide evidence for this assertion by combining the intuition springing from the string worldsheet picture and the predictions coming from the OPE series. One of the main implications of these considerations is that scattering amplitudes receive equally important contributions at strong coupling from both the minimal string area and its fluctuations in the sphere.
The strong coupling from tau decays without prejudice
Boito, Diogo [Physik Department T31, Technische Universität München, James-Franck-Straße 1, D-85748 Garching (Germany); Golterman, Maarten [Institut de Física d' Altes Energies, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain); Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Jamin, Matthias [Institució Catalana de Recerca i Estudis Avançats (ICREA), IFAE, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain); Mahdavi, Andisheh [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Maltman, Kim [Department of Mathematics and Statistics, York University, Toronto, ON Canada M3J 1P3 (Canada); CSSM, University of Adelaide, Adelaide, SA 5005 Australia (Australia); Osborne, James [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Peris, Santiago [Department of Physics, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain)
2014-08-15
We review our recent determination of the strong coupling α{sub s} from the OPAL data for non-strange hadronic tau decays. We find that α{sub s}(m{sub τ}{sup 2})=0.325±0.018 using fixed-order perturbation theory, and α{sub s}(m{sub τ}{sup 2})=0.347±0.025 using contour-improved perturbation theory. At present, these values supersede any earlier determinations of the strong coupling from hadronic tau decays, including those from ALEPH data.
The strong coupling from tau decays without prejudice
We review our recent determination of the strong coupling αs from the OPAL data for non-strange hadronic tau decays. We find that αs(mτ2)=0.325±0.018 using fixed-order perturbation theory, and αs(mτ2)=0.347±0.025 using contour-improved perturbation theory. At present, these values supersede any earlier determinations of the strong coupling from hadronic tau decays, including those from ALEPH data
Tunable metamaterials based on voltage controlled strong coupling
We present the design, fabrication, and realization of an electrically tunable metamaterial operating in the mid-infrared spectral range. Our devices combine intersubband transitions in semiconductor quantum-wells with planar metamaterials and operate in the strong light-matter coupling regime. The resonance frequency of the intersubband transition can be controlled by an external bias relative to the fixed metamaterial resonance. This allows us to switch dynamically from an uncoupled to a strongly coupled system and thereby to shift the eigenfrequency of the upper polariton branch by 2.5 THz (corresponding to 8% of the center frequency or one full linewidth) with a bias of 5 V
Experimental determination of the effective strong coupling constant
Alexandre Deur; Volker Burkert; Jian-Ping Chen; Wolfgang Korsch
2007-07-01
We extract an effective strong coupling constant from low Q{sup 2} data on the Bjorken sum. Using sum rules, we establish its Q{sup 2}-behavior over the complete Q{sup 2}-range. The result is compared to effective coupling constants extracted from different processes and to calculations based on Schwinger-Dyson equations, hadron spectroscopy or lattice QCD. Although the connection between the experimentally extracted effective coupling constant and the calculations is not clear, the results agree surprisingly well.
A scenario for inflationary magnetogenesis without strong coupling problem
Tasinato, Gianmassimo [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom); Institute of Cosmology and Gravitation, University of Portsmouth,Portsmouth, PO1 3FX (United Kingdom)
2015-03-23
Cosmological magnetic fields pervade the entire universe, from small to large scales. Since they apparently extend into the intergalactic medium, it is tantalizing to believe that they have a primordial origin, possibly being produced during inflation. However, finding consistent scenarios for inflationary magnetogenesis is a challenging theoretical problem. The requirements to avoid an excessive production of electromagnetic energy, and to avoid entering a strong coupling regime characterized by large values for the electromagnetic coupling constant, typically allow one to generate only a tiny amplitude of magnetic field during inflation. We propose a scenario for building gauge-invariant models of inflationary magnetogenesis potentially free from these issues. The idea is to derivatively couple a dynamical scalar, not necessarily the inflaton, to fermionic and electromagnetic fields during the inflationary era. Such couplings give additional freedom to control the time-dependence of the electromagnetic coupling constant during inflation. This fact allows us to find conditions to avoid the strong coupling problems that affect many of the existing models of magnetogenesis. We do not need to rely on a particular inflationary set-up for developing our scenario, that might be applied to different realizations of inflation. On the other hand, specific requirements have to be imposed on the dynamics of the scalar derivatively coupled to fermions and electromagnetism, that we are able to satisfy in an explicit realization of our proposal.
From strong to ultrastrong coupling in circuit QED architectures
The field of cavity quantum electrodynamics (cavity QED) studies the interaction between light and matter on a fundamental level: a single atom interacts with a single photon. If the atom-photon coupling is larger than any dissipative effects, the system enters the strong-coupling limit. A peculiarity of this regime is the possibility to form coherent superpositions of light and matter excitations - a kind of 'molecule' consisting of an atomic and a photonic contribution. The novel research field of circuit QED extends cavity QED concepts to solid-state based system. Here, a superconducting quantum bit is coupled to an on-chip superconducting one-dimensional waveguide resonator. Owing to the small mode-volume of the resonant cavity, the large dipole moment of the 'artificial atom' and the enormous engineering potential inherent to superconducting quantum circuits, remarkable atom-photon coupling strengths can be realized. This thesis describes the theoretical framework, the development of fabrication techniques and the implementation of experimental characterization techniques for superconducting quantum circuits for circuit QED applications. In particular, we study the interaction between superconducting flux quantum bits and high-quality coplanar waveguide resonators in the strong-coupling limit. Furthermore, we report on the first experimental realization of a circuit QED system operating in the ultrastrong-coupling regime, where the atom-photon coupling rate reaches a considerable fraction of the relevant system frequencies. In these experiments we could observe phenomena that can not be explained within the renowned Jaynes-Cummings model. (orig.)
Real-time quantum trajectories for classically allowed dynamics in strong laser fields
Plimak, L. I.; Ivanov, Misha Yu.
2015-10-01
Both the physical picture of the dynamics of atoms and molecules in intense infrared fields and its theoretical description use the concept of electron trajectories. Here, we address a key question which arises in this context: Are distinctly quantum features of these trajectories, such as the complex-valued coordinates, physically relevant in the classically allowed region of phase space, and what is their origin? First, we argue that solutions of classical equations of motion can account for quantum effects. To this end, we construct an exact solution to the classical Hamilton-Jacobi equation which accounts for dynamics of the wave packet, and show that this solution is physically correct in the limit ?. Second, we show that imaginary components of classical trajectories are directly linked to the finite size of the initial wave packet in momentum space. This way, if the electronic wave packet produced by optical tunnelling in strong infrared fields is localised both in coordinate and momentum, its motion after tunnelling ipso facto cannot be described with purely classical trajectories - in contrast to popular models in the literature.
From strong to weak coupling in holographic models of thermalization
Grozdanov, Sašo; Kaplis, Nikolaos; Starinets, Andrei O.
2016-07-01
We investigate the analytic structure of thermal energy-momentum tensor correlators at large but finite coupling in quantum field theories with gravity duals. We compute corrections to the quasinormal spectra of black branes due to the presence of higher derivative R 2 and R 4 terms in the action, focusing on the dual to N=4 SYM theory and Gauss-Bonnet gravity. We observe the appearance of new poles in the complex frequency plane at finite coupling. The new poles interfere with hydrodynamic poles of the correlators leading to the breakdown of hydrodynamic description at a coupling-dependent critical value of the wave-vector. The dependence of the critical wave vector on the coupling implies that the range of validity of the hydrodynamic description increases monotonically with the coupling. The behavior of the quasinormal spectrum at large but finite coupling may be contrasted with the known properties of the hierarchy of relaxation times determined by the spectrum of a linearized kinetic operator at weak coupling. We find that the ratio of a transport coefficient such as viscosity to the relaxation time determined by the fundamental non-hydrodynamic quasinormal frequency changes rapidly in the vicinity of infinite coupling but flattens out for weaker coupling, suggesting an extrapolation from strong coupling to the kinetic theory result. We note that the behavior of the quasinormal spectrum is qualitatively different depending on whether the ratio of shear viscosity to entropy density is greater or less than the universal, infinite coupling value of ℏ /4π k B . In the former case, the density of poles increases, indicating a formation of branch cuts in the weak coupling limit, and the spectral function shows the appearance of narrow peaks. We also discuss the relation of the viscosity-entropy ratio to conjectured bounds on relaxation time in quantum systems.
Dou, Wenjie; Subotnik, Joseph E
2016-01-14
A broadened classical master equation (BCME) is proposed for modeling nonadiabatic dynamics for molecules near metal surfaces over a wide range of parameter values and with arbitrary initial conditions. Compared with a standard classical master equation-which is valid in the limit of weak molecule-metal couplings-this BCME should be valid for both weak and strong molecule-metal couplings. (The BCME can be mapped to a Fokker-Planck equation that captures level broadening correctly.) Finally, our BCME can be solved with a simple surface hopping algorithm; numerical tests of equilibrium and dynamical observables look very promising. PMID:26772563
SOLITONS: Dynamics of strong coupling formation between laser solitons
Rosanov, Nikolai N.; Fedorov, S. V.; Shatsev, A. N.
2005-03-01
The dynamics of the strong coupling formation between two solitons with the unit topological charge is studied in detail for a wide-aperture class A laser. The sequence of bifurcations of the vector field of energy fluxes in the transverse plane was demonstrated during the formation of a soliton complex.
Practical thermodynamics of Yukawa systems at strong coupling
Khrapak, Sergey A. [Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen (Germany); Aix-Marseille-Université, CNRS, Laboratoire PIIM, UMR 7345, 13397 Marseille Cedex 20 (France); Kryuchkov, Nikita P.; Yurchenko, Stanislav O. [Bauman Moscow State Technical University, 2-nd Baumanskaya St. 5, Moscow 105005 (Russian Federation); Thomas, Hubertus M. [Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen (Germany)
2015-05-21
Simple practical approach to estimate thermodynamic properties of strongly coupled Yukawa systems, in both fluid and solid phases, is presented. The accuracy of the approach is tested by extensive comparison with direct computer simulation results (for fluids and solids) and the recently proposed shortest-graph method (for solids). Possible applications to other systems of softly repulsive particles are briefly discussed.
Practical thermodynamics of Yukawa systems at strong coupling
Simple practical approach to estimate thermodynamic properties of strongly coupled Yukawa systems, in both fluid and solid phases, is presented. The accuracy of the approach is tested by extensive comparison with direct computer simulation results (for fluids and solids) and the recently proposed shortest-graph method (for solids). Possible applications to other systems of softly repulsive particles are briefly discussed
Numerical investigation of quantumfield model of strong-coupling binucleon
The quantumfield binucleon model for the case of the nucleon spot interaction with the scalar and pseudoscalar mesons fields is considered. For the strong coupling limit the nonlinear equations describing two nucleons in the meson field are developed. Methods of numerical investigation and obtained results are discussed. 10 refs., 3 figs., 3 tabs
Strong coupling QCD and the (π+,π-) reaction
Previous six-quark bag model calculations are in disagreement with new (π+, π-) data, but conventional nucleonic calculations are generally successful. Six-quark bag models are related to perturbative QCD. I argue that the strong coupling limit of QCD (SCQCD) is a more appropriate starting point for nuclear physics. 15 refs., 3 figs
Visco-elastic effects in strongly coupled dusty plasmas
Bandyopadhyay, P; Sen, A; Kaw, P K
2016-01-01
We report on experimental evidence of visco-elastic effects in a strongly coupled dusty plasma through investigations of the propagation characteristics of low frequency dust acoustic waves and by excitations of transverse shear waves in a DC discharge Argon plasma.
Coupled Cluster Theories for Strongly Correlated Molecular Systems
Kowalski, K.; Bhaskaran-Nair, K.; Brabec, Jiří; Pittner, Jiří
Heidelberg: Springer-Verlag Berlin, 2013 - (Avella, A.; Mancini, F.), s. 237-271 ISBN 978-3-642-35106-8 R&D Projects: GA ČR GAP208/11/2222 Institutional support: RVO:61388955 Keywords : coupled cluster theories * strongly correlated molecular systems * computational chemistry Subject RIV: CF - Physical ; Theoretical Chemistry
Quantum field model of strong-coupling binucleon
The quantum field binucleon model for the case of the nucleon spot interaction with the scalar and pseudoscalar meson fields is considered. It is shown that the nonrelativistic problem of the two nucleon interaction reduces to the one-particle problem. For the strong coupling limit the nonlinear equations describing two nucleons in the meson field are developed
Linear and electronic transport in strongly coupled binary ionic mixtures
A systematic investigation of linear transport properties in strongly coupled binary ionic mixtures of pointlike ions interacting solely through Coulomb interactions is presented. The basic formalism rests upon suitable extensions of the Boltzmann-Ziman equation explained in this work. Validity conditions for the Lorentzian approximation are thoroughly discussed as well as entropy arguments. High temperature inelastic contributions are emphasized out. (author)
Short-Pulse Amplification by Strongly-Coupled Brillouin Scattering
Edwards, Matthew R; Mikhailova, Julia M; Fisch, Nathaniel J
2016-01-01
We examine the feasibility of strongly-coupled stimulated Brillouin scattering as a mechanism for the plasma-based amplification of sub-picosecond pulses. In particular, we use fluid theory and particle-in-cell simulations to compare the relative advantages of Raman and Brillouin amplification over a broad range of achievable parameters.
Weak and strong coupling equilibration in nonabelian gauge theories
Keegan, Liam; Romatschke, Paul; van der Schee, Wilke; Zhu, Yan
2016-01-01
We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.
Weak and strong coupling equilibration in nonabelian gauge theories
Keegan, Liam; Kurkela, Aleksi; Romatschke, Paul; van der Schee, Wilke; Zhu, Yan
2016-04-01
We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.
Strong coupling of paramagnetic spins to a superconducting microwave resonator
Greifenstein, Moritz; Zollitsch, Christoph; Lotze, Johannes; Hocke, Fredrik; Goennenwein, Sebastian T.B.; Huebl, Hans [Walther-Meissner-Institut (WMI), Garching (Germany); Gross, Rudolf [Walther-Meissner-Institut (WMI), Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany)
2012-07-01
Under application of an external magnetic field, non-interacting electron spins behave as an ensemble of identical two-level-systems with tuneable transition frequency. When such an ensemble collectively interacts with a single mode of an electromagnetic resonator, the entire system can be described as two coupled quantum harmonic oscillators. The criterion for the observation of the so-called strong coupling regime is that the collective coupling strength g exceeds both the loss rate of the resonator {kappa} and of the spin ensemble {gamma}. In our experiment we realize a coupled spin-photon-system by introducing the spin marker DPPH (2,2-diphenyl-1-picrylhydrazyl) into the mode volume of a superconducting coplanar microwave resonator and investigate the interaction at 2.5, 5.0 and 7.5 GHz. For tuning the resonance, we apply an in-plane magnetic field and observe interaction at around {+-}90, {+-}180 and {+-}270 mT. While the coupling with the fundamental mode and the first harmonic mode of the resonator is identified as weak, the second harmonic shows g=21 MHz, {kappa} = 6 MHz and {gamma} = 5 MHz, i.e. the strong coupling regime. We further investigate the dependence of g on temperature and on microwave input power.
Energy loss of heavy ions in strongly coupled plasmas
We investigate the energy loss of heavy ions in strongly coupled plasmas, by performing molecular dynamics (MD) computer simulations. These studies are of interest in heavy-ion-driven inertial confinement fusion, as well as for electron cooling. We consider the non-linear behavior for strong target-ion coupling parameters, i.e. ZΓ3/2>or∼1, in non-ideal plasmas with Γ>or∼0.1 (Z is the charge number of the ion and Γ is the plasma parameter of the target). The new features that we found from our simulation results can be summarized as follows. (1) For strong ion-target coupling, the energy loss of the ions at low velocities scales with Z as Z1.5, in agreement with recent experimental and other theoretical results. This clearly deviates from the Z2 ln(const./Z) scaling of the conventional weak coupling theories. (2) The change in the Z scaling has its origin in a non-linear screening that occurs for strong coupling and is associated with an increase in the (static) screening length above the Debye-Hueckel result of the linear theory. (3) The non-linear screening is accompanied by electrons trapped by the ion into high Rydberg states, through multi-particle collisions. Compared with the case of linear coupling, this trapping causes an enhanced electron density around the ion. (4) The transient time dependence of the stopping power after switching on the ion-target interaction has characteristic time-scales that are a fraction of the plasma period. (orig.)
Energy Exchange in Driven Open Quantum Systems at Strong Coupling
Carrega, Matteo; Solinas, Paolo; Sassetti, Maura; Weiss, Ulrich
2016-06-01
The time-dependent energy transfer in a driven quantum system strongly coupled to a heat bath is studied within an influence functional approach. Exact formal expressions for the statistics of energy dissipation into the different channels are derived. The general method is applied to the driven dissipative two-state system. It is shown that the energy flows obey a balance relation, and that, for strong coupling, the interaction may constitute the major dissipative channel. Results in analytic form are presented for the particular value K =1/2 of strong Ohmic dissipation. The energy flows show interesting behaviors including driving-induced coherences and quantum stochastic resonances. It is found that the general characteristics persists for K near 1/2 .
Neutron Limit on the Strongly-Coupled Chameleon Field
Li, K; Cory, D G; Haun, R; Heacock, B; Huber, M G; Nsofini, J; Pushin, D A; Saggu, P; Sarenac, D; Shahi, C B; Skavysh, V; Snow, W M; Young, A R
2016-01-01
The physical origin of the dark energy that causes the accelerated expansion rate of the universe is one of the major open questions of cosmology. One set of theories postulates the existence of a self-interacting scalar field for dark energy coupling to matter. In the chameleon dark energy theory, this coupling induces a screening mechanism such that the field amplitude is nonzero in empty space but is greatly suppressed in regions of terrestrial matter density. However measurements performed under appropriate vacuum conditions can enable the chameleon field to appear in the apparatus, where it can be subjected to laboratory experiments. Here we report the most stringent upper bound on the free neutron-chameleon coupling in the strongly-coupled limit of the chameleon theory using neutron interferometric techniques. Our experiment sought the chameleon field through the relative phase shift it would induce along one of the neutron paths inside a perfect crystal neutron interferometer. The amplitude of the cham...
A scenario for inflationary magnetogenesis without strong coupling problem
Tasinato, Gianmassimo
2014-01-01
Cosmological magnetic fields pervade the entire universe, from small to large scales. Since they apparently extend into the intergalactic medium, it is tantalizing to believe that they have a primordial origin, possibly being produced during inflation. However, finding consistent scenarios for inflationary magnetogenesis is a challenging theoretical problem. The requirements to avoid an excessive production of electromagnetic energy, and to avoid entering a strong coupling regime characterized by large values for the electromagnetic coupling constant, typically allow one to generate only a tiny amplitude of magnetic field during inflation. We propose a scenario for building gauge-invariant models of inflationary magnetogenesis potentially free from these issues. The idea is to derivatively couple a dynamical scalar, not necessarily the inflaton, to fermionic and electromagnetic fields during the inflationary era. Such couplings give additional freedom to control the time-dependence of the electromagnetic coup...
Strongly coupled radiation from moving mirrors and holography in the Karch-Randall model
Motivated by the puzzles in understanding how Black Holes evaporate into a strongly coupled Conformal Field Theory, we study particle creation by an accelerating mirror. We model the mirror as a gravitating Domain Wall and consider a CFT coupled to it through gravity, in asymptotically Anti de Sitter space. This problem (backreaction included) can be solved exactly at one loop. At strong coupling, this is dual to a Domain Wall localized on the brane in the Karch-Randall model, which can be fully solved as well. Hence, in this case one can see how the particle production is affected by A) strong coupling and B) its own backreaction. We find that A) the amount of CFT radiation at strong coupling is not suppressed relative to the weak coupling result; and B) once the boundary conditions in the AdS5 bulk are appropriately mapped to the conditions for the CFT on the boundary of AdS4, the Karch-Randall model and the CFT side agree to leading order in the backreaction. This agreement holds even for a new class of self-consistent solutions (the 'Bootstrap' Domain Wall spacetimes) that have no classical limit. This provides a quite precise check of the holographic interpretation of the Karch-Randall model. We also comment on the massive gravity interpretation. As a byproduct, we show that relativistic Cosmic Strings (pure tension codimension 2 branes) in Anti de Sitter are repulsive and generate long-range tidal forces even at classical level. This is the phenomenon dual to particle production by Domain Walls.
Strong and Coherent Coupling between Localized and Propagating Phonon Polaritons
Gubbin, Christopher R.; Martini, Francesco; Politi, Alberto; Maier, Stefan A.; De Liberato, Simone
2016-06-01
Following the recent observation of localized phonon polaritons in user-defined silicon carbide nanoresonators, here we demonstrate strong and coherent coupling between those localized modes and propagating phonon polaritons bound to the surface of the nanoresonator's substrate. In order to obtain phase matching, the nanoresonators have been fabricated to serve the double function of hosting the localized modes, while also acting as a grating for the propagating ones. The coherent coupling between long lived, optically accessible localized modes, and low-loss propagative ones, opens the way to the design and realization of phonon-polariton based coherent circuits.
Very strong coupling in GaAs based optical microcavities
Zhang, H; Yamamoto, Y; Na, N
2012-01-01
We show that when following a simple cavity design metric, a quantum well exciton-microcavity photon coupling constant can be larger than the exciton binding energy in GaAs based optical microcavities. Such a very strong coupling significantly reduces the relative electron-hole motion and makes the polaritons robust against phonon collisions. The corresponding polariton dissociation and saturation boundaries on the phase diagram are much improved, and our calculations suggest the possibility of constructing a room temperature, high power exciton-polariton laser without resorting to wide bandgap semiconductors.
Strong Exciton-photon Coupling in Semiconductor Microcavities
Jensen, Jacob Riis; Borri, Paola; Hvam, Jørn Märcher; Langbein, Wolfgang
1999-01-01
directionality of the spontaneous emission in the diodes.At low temperatures, a strong coupling between the excitons in the quantum well and the electromagnetic field in the cavity may be achieved. This coupling leads to new quantum mechanical states, so-called polaritons, the properties of which are still not...... place. Due to the steep dispersion, the amount of phase space available for polariton scattering is reduced, yielding longer dephasing times and hence narrower lines. The possibility of tailoring the polariton dispersion in order to reduce the line width is very interesting, for instance for all...
Strong Coupling between On Chip Notched Ring Resonator and Nanoparticle
Wang, S; Smith, H; Yi, Y
2010-01-01
We have demonstrated a new photonic structure to achieve strong optical coupling between nanoparticle and photonic molecule by utilizing a notched micro ring resonators. By creating a notch in the ring resonator and putting a nanoparticle inside the notch, large spectral shifts and splittings at nm scale can be achieved, compared to only pm scale observed by fiber tip evanescently coupled to the surface of microsphere, thereby significantly lowered the quality factor requirement for single nanoparticle detection. The ability for sorting the type of nanoparticles due to very different mode shift and splitting behavior of dielectric and metallic nanoparticles is also emphasized.
Nuclear physics from lattice QCD at strong coupling
Understanding the properties of nuclear matter from first principles, starting from the QCD Lagrangian via lattice simulations, is one of the main goals of lattice QCD. Unfortunately this task is turned out to be too ambitious. However, in the limiting case of an infinite bare gauge coupling, this goal can be reached: the full phase diagram as a function of temperature and baryon chemical potential can be determined and also the nuclear potential can be obtained. I present new results obtained from lattice QCD at strong coupling and explain in what respect this model describes some of the properties of nuclear matter, such as the origin of nuclear interactions.
From strong to ultrastrong coupling in circuit QED architectures
Niemczyk, Thomas
2011-08-10
The field of cavity quantum electrodynamics (cavity QED) studies the interaction between light and matter on a fundamental level: a single atom interacts with a single photon. If the atom-photon coupling is larger than any dissipative effects, the system enters the strong-coupling limit. A peculiarity of this regime is the possibility to form coherent superpositions of light and matter excitations - a kind of 'molecule' consisting of an atomic and a photonic contribution. The novel research field of circuit QED extends cavity QED concepts to solid-state based system. Here, a superconducting quantum bit is coupled to an on-chip superconducting one-dimensional waveguide resonator. Owing to the small mode-volume of the resonant cavity, the large dipole moment of the 'artificial atom' and the enormous engineering potential inherent to superconducting quantum circuits, remarkable atom-photon coupling strengths can be realized. This thesis describes the theoretical framework, the development of fabrication techniques and the implementation of experimental characterization techniques for superconducting quantum circuits for circuit QED applications. In particular, we study the interaction between superconducting flux quantum bits and high-quality coplanar waveguide resonators in the strong-coupling limit. Furthermore, we report on the first experimental realization of a circuit QED system operating in the ultrastrong-coupling regime, where the atom-photon coupling rate reaches a considerable fraction of the relevant system frequencies. In these experiments we could observe phenomena that can not be explained within the renowned Jaynes-Cummings model. (orig.)
QCD and strongly coupled gauge theories: challenges and perspectives
Brambilla, N.; Vairo, A. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Eidelman, S. [SB RAS, Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Foka, P. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Gardner, S. [University of Kentucky, Department of Physics and Astronomy, Lexington, KY (United States); Kronfeld, A.S. [Fermi National Accelerator Laboratory, Theoretical Physics Department, Batavia, IL (United States); Alford, M.G.; Schwenzer, K. [Washington University, Department of Physics, St Louis, MO (United States); Alkofer, R. [University of Graz, Graz (Austria); Butenschoen, M. [University of Vienna, Faculty of Physics, Wien (Austria); Cohen, T.D. [University of Maryland, Maryland Center for Fundamental Physics and Department of Physics, College Park, MD (United States); Erdmenger, J. [Max-Planck-Institute for Physics, Munich (Germany); Fabbietti, L. [Technische Universitaet Muenchen, Excellence Cluster ' ' Origin and Structure of the Universe' ' , Garching (Germany); Faber, M.; Hoellwieser, R. [Technische Universitaet Wien, Atominstitut, Vienna (Austria); Goity, J.L. [Hampton University, Hampton, VA (United States); Jefferson Laboratory, Newport News, VA (United States); Ketzer, B. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Lin, H.W. [University of Washington, Department of Physics, Seattle, WA (United States); Llanes-Estrada, F.J. [Universidad Complutense de Madrid, Department Fisica Teorica I, Madrid (Spain); Meyer, H.B.; Wittig, H.; Hippel, G.M. von [Johannes Gutenberg-Universitaet Mainz, PRISMA Cluster of Excellence, Institut fuer Kernphysik and Helmholtz Institut Mainz, Mainz (Germany); Pakhlov, P.; Polikarpov, M.I. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Moscow Institute for Physics and Technology, Dolgoprudny (Russian Federation); Pallante, E.; Papadodimas, K. [University of Groningen, Centre for Theoretical Physics, Groningen (Netherlands); Sazdjian, H. [Universite Paris-Sud, Institut de Physique Nucleaire CNRS/IN2P3, Orsay (France); Schmitt, A. [Technische Universitaet Wien, Institut fuer Theoretische Physik, Vienna (Austria); Snow, W.M. [Indiana University, Center for Exploration of Energy and Matter and Department of Physics, Bloomington, IN (United States); Vogt, R. [Lawrence Livermore National Laboratory, Physics Division, Livermore, CA (United States); University of California, Physics Department, Davis, CA (United States); Vuorinen, A. [University of Helsinki, Department of Physics and Helsinki Institute of Physics, Helsinki (Finland); Arnold, P. [University of Virginia, Department of Physics, Charlottesville, VA (United States); Christakoglou, P. [NIKHEF, Amsterdam (Netherlands); Di Nezza, P. [Istituto Nazionale di Fisica Nucleare (INFN), Frascati (Italy); Fodor, Z. [Wuppertal University, Wuppertal (Germany); Eoetvoes University, Budapest (Hungary); Forschungszentrum Juelich, Juelich (Germany); Garcia i Tormo, X. [Universitaet Bern, Albert Einstein Center for Fundamental Physics, Institut fuer Theoretische Physik, Bern (Switzerland); Janik, M.A. [Warsaw University of Technology, Faculty of Physics, Warsaw (Poland); Kalweit, A. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Keane, D. [Kent State University, Department of Physics, Kent, OH (United States); Kiritsis, E. [University of Crete, Crete Center for Theoretical Physics, Department of Physics, Heraklion (Greece); Universite Paris Diderot, Laboratoire APC, Sorbonne Paris-Cite (France); CERN, Theory Group, Physics Department, Geneva 23 (Switzerland); Mischke, A. [Utrecht University, Faculty of Science, Utrecht (Netherlands); Mizuk, R. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Moscow Physical Engineering Institute, Moscow (Russian Federation); Odyniec, G. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)
2014-10-15
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments. (orig.)
Strong coupling between localized and propagating plasmon polaritons.
Balci, Sinan; Karademir, Ertugrul; Kocabas, Coskun
2015-07-01
We investigate plasmon-plasmon (PP) coupling in the strongly interacting regimes by using a tunable plasmonic platform consisting of triangular Ag nanoprisms placed nanometers away from Ag thin films. The nanoprisms are colloidally synthesized using a seed-mediated growth method and having size-tunable localized surface plasmon polariton (SPP) resonances immobilized on Si(3)N(4) films. The PP coupling between the localized SPPs of metal nanoprisms and the propagating SPPs of the metal film is controlled by the nanoprism concentration and the plasmon damping in the metal film. Results reveal that Rabi splitting energy determining the strength of the coupling can reach up to several hundreds meV, thus demonstrating the ultrastrong coupling occurring between localized and propagating SPPs. The metal nanoparticle-metal thin film hybrid system over the square-centimeter areas presented here provides a unique configuration to study PP coupling all the way from the weak to ultrastrong coupling regimes in a broad range of wavelengths. PMID:26125396
Four lectures on strongly coupled Quark Gluon Plasma
The four lectures are divided evenly between phenomenology and theory. Lecture 1 describes the hydrodynamical treatment of the high energy heavy ion collisions: we discuss in it the appearance of the notion of the 'strongly coupled' QGP. Another phenomenological lecture is about perturbations of this expansion, by fluctuations of different types. We will in particularly argue that matter in a near-Tc situation is quite special, with an electric field imbedded in it for a long time: this situation should be described by dual-magnetohydrodynamics (DMHD). Two theoretical lectures focus on two dualities. The electric-magnetic duality, describing gradual transition from electric plasma at high-T to a magnetic-dominated plasma in the near-Tc domain. The last lecture is about applications of AdS/CFT duality, between strongly coupled N=4SYM gauge theory in 4 dimensions and string theory in the AdS5*S5 background.
Strongly coupled gauge theories: What can lattice calculations teach us?
CERN. Geneva
2015-01-01
Electroweak symmetry breaking and the dynamical origin of the Higgs boson are central questions today. Strongly coupled systems predicting the Higgs boson as a bound state of a new gauge-fermion interaction are candidates to describe beyond Standard Model physics. The phenomenologically viable models are strongly coupled, near the conformal boundary, requiring non-perturbative studies to reveal their properties. Lattice studies show that many of the beyond-Standard Model candidates have a relatively light isosinglet scalar state that is well separated from the rest of the spectrum. When the scale is set via the vev of electroweak symmetry breaking, a 2 TeV vector resonance appears to be a general feature of many of these models with several other resonances that are not much heavier.
Measurement of the strong coupling constant using τ decays
The strong coupling constant is determined from the leptonic branching ratios, the lifetime, and the invariant mass distribution of the hadronic final state of the τ lepton,, using data accumulated at LEP with the ALEPH detector. The strong coupling constant measurement, αs(m2τ) = 0.330 ± 0.046, evolved to the Z mass, yields αs(M2Z) = 0.118 ± 0.005. The error includes experimental and theoretical uncertainties, the latter evaluated in the framework of the Shifman, Vainshtein and Zakharov (SVZ) approach. The method allows the non-perturbative contribution to the hadronic decay rate to be determined to be 0.3 ± 0.5%
Measurement of the strong coupling constant using τ decays
Buskulic, D.; Decamp, D.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Mours, B.; Pietrzyk, B.; Alemany, R.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Maggi, M.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bauerdick, L. A. T.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Haywood, S.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Lohse, T.; Lusiani, A.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Efthymiopoulos, I.; Kyriakis, A.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Mermikides, M.; Sawyer, L.; Wasserbaech, S.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Belk, A. T.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Dugeay, S.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Nash, J.; Payne, D. G.; Phillips, M. J.; Sedgbeer, J. K.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Aubert, J.-J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Rotscheidt, H.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; Denis, R. St.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bosisio, L.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Focardi, E.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Carter, J. M.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Edwards, M.; Fisher, S. M.; Jones, T. J.; Norton, P. R.; Salmon, D. P.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Perez, P.; Perrier, F.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Carney, R. E.; Cartwright, S.; Combley, F.; Hatfield, F.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Cinabro, D.; Conway, J. S.; Cowen, D. F.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Jared, R. C.; Leclaire, B. W.; Lishka, C.; Pan, Y. B.; Pater, J. R.; Saadi, Y.; Sharma, V.; Schmitt, M.; Shi, Z. H.; Walsh, A. M.; Weber, F. V.; Lan Wu, Sau; Wu, X.; Zheng, M.; Zobernig, G.; Aleph Collaboration
1993-06-01
The strong coupling constant is determined from the leptonic branching ratios, the lifetime, and the invariant mass distribution of the hadronic final state of the τ lepton, using data accumulated at LEP with the ALEPH detector. The strong coupling constant measurement, αs( mτ2) = 0.330±0.046, evolved to the Z mass yields αs( MZ2) = 0.188±0.005. The error includes experimental and theoretical uncertainties, the latter evaluated in the framework of the Shifman, Vainshtein and Zakharov (SVZ) approach. The method allows the non-perturbative contribution to the hadronic decay rate to be determined to be 0.3±0.5%.
Collinear Limit of Scattering Amplitudes at Strong Coupling
Basso, Benjamin; Sever, Amit; Vieira, Pedro
2014-12-01
In this Letter, we consider the collinear limit of gluon scattering amplitudes in planar N =4 super-Yang-Mills theory at strong coupling. We argue that in this limit scattering amplitudes map into correlators of twist fields in the two dimensional nonlinear O (6 ) sigma model, similar to those appearing in recent studies of entanglement entropy. We provide evidence for this assertion by combining the intuition springing from the string world-sheet picture and the predictions coming from the operator product expansion series. One of the main implications of these considerations is that scattering amplitudes receive equally important contributions at strong coupling from both the minimal string area and its fluctuations in the sphere.
Strong Coupling Isotropization of Non-Abelian Plasmas Simplified
Heller, M.P.; Mateos, D.; van der Schee, W.; Trancanelli, D.
2012-01-01
We study the isotropization of a homogeneous, strongly coupled, non-Abelian plasma by means of its gravity dual. We compare the time evolution of a large number of initially anisotropic states as determined, on the one hand, by the full non-linear Einstein's equations and, on the other, by the Einstein's equations linearized around the final equilibrium state. The linear approximation works remarkably well even for states that exhibit large anisotropies. For example, it predicts with a 20% ac...
Many-body correlations in strongly-coupled plasmas
Two aspects of many-particle correlations of ions in strongly-coupled plasmas are analysed on the basis of numerical experiments. First, the pair correlation function and the structure factor in the polarizing background of electrons are obtained and electric and thermal conductivities are calculated. Then the triplet correlation of ions in the uniform background is discussed in comparison with simple closure approximations. (author)
Probing strongly coupled anisotropic plasmas from higher curvature gravity
Misobuchi, Anderson Seigo
2015-01-01
We consider five-dimensional AdS-axion-dilaton gravity with a Gauss-Bonnet term and use a black brane solution displaying spatial anisotropy as the gravity dual of a strongly coupled anisotropic plasma. We compute several observables relevant to the study of the plasma, namely, the drag force, the jet quenching parameter, the quarkonium potential and the thermal photon production. The effects of higher derivative corrections and of the anisotropy are discussed and compared with previous results.
Probing strongly coupled anisotropic plasmas from higher curvature gravity
Jahnke, Viktor; Misobuchi, Anderson Seigo
2016-06-01
We consider five-dimensional AdS-axion-dilaton gravity with a Gauss-Bonnet term and use a black brane solution displaying spatial anisotropy as the gravity dual of a strongly coupled anisotropic plasma. We compute several observables relevant to the study of the plasma, namely, the drag force, the jet quenching parameter, the quarkonium potential, and the thermal photon production. The effects of higher derivative corrections and of the anisotropy are discussed and compared with previous results.
Self-diffusion in strongly coupled Yukawa systems (complex plasmas)
Khrapak, Sergey A; Morfill, Gregor E
2012-01-01
We show that the idea of mapping between the Newtonian and Brownian diffusivities proposed and tested on a class of particle systems interacting via soft and ultra-soft potentials (IPL, Gaussian core, Hertzian, and effective star-polymer) by Pond {\\it et al}., [Soft Matter {\\bf 7}, 9859 (2011)] is also applicable to the Yukawa (screened Coulomb) interaction. Some of the implications of this result with respect to self-diffusion in strongly coupled complex (dusty) plasmas are discussed.
Analytic Solution of Strongly Coupling Schr(o)dinger Equations
LIAO Jin-Feng; ZHUANG Peng-Fei
2004-01-01
A recently developed expansion method for analytically solving the ground states of strongly coupling Schrodinger equations by Friedberg,Lee,and Zhao is extended to excited states and applied to power-law central forces for which scaling properties are proposed.As examples for application of the extended method,the Hydrogen atom problem is resolved and the low-lying states of Yukawa potential are approximately obtained.
Circuit cavity electromechanics in the strong coupling regime
Teufel, J D; Allman, M S; Cicak, K; Sirois, A J; Whittaker, J D; Simmonds, R W
2010-01-01
Demonstrating and exploiting the quantum nature of larger, more macroscopic mechanical objects would help us to directly investigate the limitations of quantum-based measurements and quantum information protocols, as well as test long standing questions about macroscopic quantum coherence. The field of cavity opto- and electro-mechanics, in which a mechanical oscillator is parametrically coupled to an electromagnetic resonance, provides a practical architecture for the manipulation and detection of motion at the quantum level. Reaching this quantum level requires strong coupling, interaction timescales between the two systems that are faster than the time it takes for energy to be dissipated. By incorporating a free-standing, flexible aluminum membrane into a lumped-element superconducting resonant cavity, we have increased the single photon coupling strength between radio-frequency mechanical motion and resonant microwave photons by more than two orders of magnitude beyond the current state-of-the-art. A par...
Multimode Strong Coupling in Superconducting Cavity Piezo-electromechanics
Han, Xu; Tang, Hong X
2016-01-01
High frequency mechanical resonators subjected to low thermal phonon occupancy are easier to be prepared to the ground state by direct cryogenic cooling. Their extreme stiffness, however, poses a significant challenge for external interrogations. Here we demonstrate a superconducting cavity piezo-electromechanical system in which multiple modes of a bulk acoustic resonator oscillating at $10\\,\\textrm{GHz}$ are coupled to a planar microwave superconducting resonator with a cooperativity exceeding $2\\times10^{3}$, deep in the strong coupling regime. By implementation of the non-contact coupling scheme to reduce mechanical dissipation, the system exhibits excellent coherence characterized by a frequency-quality factor product of $7.5\\times10^{15}\\,\\textrm{Hz}$. Interesting dynamics of temporal oscillations of the microwave energy is observed, implying the coherent conversion between phonons and photons. The demonstrated high frequency cavity piezo-electromechanics is compatible with superconducting qubits, repre...
Ultra-strong coupling in a transmon circuit architecture
Bosman, Sal; Gely, Mario; Singh, Vibhor; Bruno, Alessandro; Steele, Gary
New unexplored phenomena are predicted in cQED for the ultra-strong coupling (USC) regime and beyond. Here, we explore two strategies to increase the coupling between a transmon qubit and a microwave resonator. In the first approach, we increase the impedance of the resonator, enhancing it's voltage zero-point fluctuations, and measure a vacuum Rabi splitting of 916 MHz. In a second approach, we create a transmon qubit by making a superconducting island suspended above the center conductor of the resonator and which is shorted to ground by two Josephson junctions. Doing so, we maximize the dipole moment of the qubit and observe a vacuum Rabi splitting of 1.2 GHz with a qubit linewidth of 1 MHz. This first transmon qubit in the USC regime improves the coherence time by a factor of 100 compared to other systems in the USC limit. Finally we predict that by combining both approaches, a coupling of ~ 3 . 6 GHz is possible, reaching close to the deep strong coupling limit. The work was supported by the Dutch science foundation NWO/FOM.
A modification of classical conjugate gradient method using strong Wolfe line search
Shoid, Syazni; Rivaie, Mohd.; Mamat, Mustafa
2016-06-01
Recently many researches try to develop and improve the Conjugate Gradient (CG) methods because of its convergence properties and low computation costing. In this paper, another CG coefficient (βk) will be proposed which is categorized as modification in such a way to improve the performance of the classical CG methods. This paper is focused on generating βk with several desirable properties: (1) generate descent search direction at each iterations; and (2) converge globally by using strong Wolfe line search. Numerical comparisons of three CG methods show the robustness and the efficiency of the new method in solving all given problems.
Neutron Limit on the Strongly-Coupled Chameleon Field
Pushin, Dmitry
2016-03-01
One of the major open questions of cosmology is the physical origin of the dark energy. There are a few sets of theories which might explain this origin that could be tested experimentally. The chameleon dark energy theory postulates self-interacting scalar field that couples to matter. This coupling induces a screening mechanism chosen so that the field amplitude is nonzero in empty space but is greatly suppressed in regions of terrestrial matter density. On behalf of the INDEX collaboration, I will report the most stringent upper bound on the free neutron-chameleon coupling in the strongly-coupled limit of the chameleon theory using neutron interferometric techniques. In our experiment we measure neutron phase induced by chameleon field. We report a 95 % confidence level upper bound on the neutron-chameleon coupling ranging from β < 4 . 7 ×106 for a Ratra-Peebles index of n = 1 in the nonlinear scalar field potential to β < 2 . 4 ×107 for n = 6 , one order of magnitude more sensitive than the most recent free neutron limit for intermediate n. This work was supported by NIST; NSF Grants: PHY-1205342, PHY-1068712, PHY-1307426; DOE award DE-FG02-97ER41042; NSERC CREATE and DISCOVERY programs; CERC; IUCSS and IU FRS program.
Paradoxical probabilistic behavior for strongly correlated many-body classical systems
Jauregui, Max; Tsallis, Constantino
2015-09-01
Using a simple probabilistic model, we illustrate that a small part of a strongly correlated many-body classical system can show a paradoxical behavior, namely asymptotic stochastic independence. We consider a triangular array such that each row is a list of n strongly correlated random variables. The correlations are preserved even when n → ∞, since the standard central limit theorem does not hold for this array. We show that, if we choose a fixed number m < n of random variables of the nth row and trace over the other n - m variables, and then consider n → ∞, the m chosen ones can, paradoxically, turn out to be independent. However, the scenario can be different if m increases with n. Finally, we suggest a possible experimental verification of our results near criticality of a second-order phase transition.
Quantum and classical resonant escapes of a strongly driven Josephson junction
Yu, H. F.; Zhu, X. B.; Peng, Z. H.; Cao, W. H.; Cui, D. J.; Tian, Ye; Chen, G. H.; Zheng, D. N.; Jing, X. N.; Lu, Li; Zhao, S. P.; Han, Siyuan
2010-04-01
The properties of phase escape in a dc superconducting quantum interference device (SQUID) at 25 mK, which is well below quantum-to-classical crossover temperature Tcr , in the presence of strong resonant ac driving have been investigated. The SQUID contains two Nb/Al-AlOx/Nb tunnel junctions with Josephson inductance much larger than the loop inductance so it can be viewed as a single junction having adjustable critical current. We find that with increasing microwave power W and at certain frequencies ν and ν/2 , the single primary peak in the switching current distribution, which is the result of macroscopic quantum tunneling of the phase across the junction, first shifts toward lower bias current I and then a resonant peak develops. These results are explained by quantum resonant phase escape involving single and two photons with microwave-suppressed potential barrier. As W further increases, the primary peak gradually disappears and the resonant peak grows into a single one while shifting further to lower I . At certain W , a second resonant peak appears, which can locate at very low I depending on the value of ν . Analysis based on the classical equation of motion shows that such resonant peak can arise from the resonant escape of the phase particle with extremely large oscillation amplitude resulting from bifurcation of the nonlinear system. Our experimental result and theoretical analysis demonstrate that at T≪Tcr , escape of the phase particle could be dominated by classical process, such as dynamical bifurcation of nonlinear systems under strong ac driving.
Strongly Coupled Models with a Higgs-like Boson*
Pich Antonio
2013-11-01
Full Text Available Considering the one-loop calculation of the oblique S and T parameters, we have presented a study of the viability of strongly-coupled scenarios of electroweak symmetry breaking with a light Higgs-like boson. The calculation has been done by using an effective Lagrangian, being short-distance constraints and dispersive relations the main ingredients of the estimation. Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models with massive resonances are not in conflict with experimentalconstraints on these parameters and the recently observed Higgs-like resonance. So there is room for these models, but they are stringently constrained. The vector and axial-vector states should be heavy enough (with masses above the TeV scale, the mass splitting between them is highly preferred to be small and the Higgs-like scalar should have a WW coupling close to the Standard Model one. It is important to stress that these conclusions do not depend critically on the inclusion of the second Weinberg sum rule.
Collective modes in a strongly coupled dusty plasma
It is widely recognized that in a typical dusty plasma encountered in the laboratory or outer space, the dust component is in a strongly coupled state because the interaction energy of neighboring dust particles due to shielded Coulomb ('Yukawa') forces is much larger than their thermal energy. Low frequency collective modes involving the motion of dust particles are therefore greatly influenced by the strong correlation effects in the dust component. In this paper a dispersion relation for low-frequency collective modes using a generalized hydrodynamics model for the dust component has been derived. Strong correlation effects are described in terms of viscoelastic transport coefficients and a finite relaxation time for the memory kernel. Novel collective effects such as new corrections to dispersion terms for longitudinal dust acoustic waves and the existence of transverse shear waves supported by strong correlations have been identified. New physical processes involving nonuniform charge number equilibria and delayed charging effects which could drive the shear wave instability have also been studied. A report on some new experiments where self-excited transverse shear modes are seen when the dust component of the plasma is in a strongly correlated fluid-like state is also presented
Charge transport in strongly coupled quantum dot solids
Kagan, Cherie R.; Murray, Christopher B.
2015-12-01
The emergence of high-mobility, colloidal semiconductor quantum dot (QD) solids has triggered fundamental studies that map the evolution from carrier hopping through localized quantum-confined states to band-like charge transport in delocalized and hybridized states of strongly coupled QD solids, in analogy with the construction of solids from atoms. Increased coupling in QD solids has led to record-breaking performance in QD devices, such as electronic transistors and circuitry, optoelectronic light-emitting diodes, photovoltaic devices and photodetectors, and thermoelectric devices. Here, we review the advances in synthesis, assembly, ligand treatments and doping that have enabled high-mobility QD solids, as well as the experiments and theory that depict band-like transport in the QD solid state. We also present recent QD devices and discuss future prospects for QD materials and device design.
Nonlinear wave propagation in strongly coupled dusty plasmas.
Veeresha, B M; Tiwari, S K; Sen, A; Kaw, P K; Das, A
2010-03-01
The nonlinear propagation of low-frequency waves in a strongly coupled dusty plasma medium is studied theoretically in the framework of the phenomenological generalized hydrodynamic (GH) model. A set of simplified model nonlinear equations are derived from the original nonlinear integrodifferential form of the GH model by employing an appropriate physical ansatz. Using standard perturbation techniques characteristic evolution equations for finite small amplitude waves are then obtained in various propagation regimes. The influence of viscoelastic properties arising from dust correlation contributions on the nature of nonlinear solutions is discussed. The modulational stability of dust acoustic waves to parallel perturbation is also examined and it is shown that dust compressibility contributions influenced by the Coulomb coupling effects introduce significant modification in the threshold and range of the instability domain. PMID:20365882
On the Classical Coupling between Gravity and Electromagnetism
Maria Becker
2015-06-01
Full Text Available Coupling between electromagnetism and gravity, manifested as the distorted Coulomb field of a charge distribution in a gravitational field, has never been observed. A physical system consisting of an electron in a charged shell provides a coupling that is orders of magnitude stronger than for any previously-considered system. A shell voltage of one megavolt is required to establish a gravitationally-induced electromagnetic force equal in magnitude to the force of gravity on an electron. The experimental feasibility of detecting these forces on an electron is discussed. The effect establishes a relation between Einstein’s energy-mass equivalence and the coupling between electromagnetism and gravity.
Experiment on dust acoustic solitons in strongly coupled dusty plasma
Dusty plasma, which contains nanometer to micrometer sized dust particles along with electrons and ions, supports a low frequency wave called Dust Acoustic wave, analogous to ion acoustic wave in normal plasma. Due to high charge and low temperature of the dust particles, dusty plasma can easily transform into a strongly coupled state when the Coulomb interaction potential energy exceeds the dust kinetic energy. Dust acoustic perturbations are excited in such strongly coupled dusty plasma by applying a short negative pulse (100 ms) of amplitude 5 - 20 V to an exciter. The perturbation steepens due to nonlinear effect and forms a solitary structure by balancing dispersion present in the medium. For specific discharge conditions, excitation amplitude above a critical value, the perturbation is found to evolve into a number of solitons. The experimental results on the excitation of multiple dust acoustic solitons in the strongly coupled regime are presented in this work. The experiment is carried out in radio frequency discharged plasma produced in a glass chamber at a pressure 0.01 - 0.1 mbar. Few layers of dust particles (∼ 5 μm in diameter) are levitated above a grounded electrode inside the chamber. Wave evolution is observed with the help of green laser sheet and recorded in a high resolution camera at high frame rate. The high amplitude soliton propagates ahead followed by smaller amplitude solitons with lower velocity. The separation between the solitons increases as time passes by. The characteristics of the observed dust acoustic solitons such as amplitude-velocity and amplitude- Mach number relationship are compared with the solutions of Korteweg-de Vries (KdV) equation. (author)
A new constraint on strongly coupled field theories
We propose a new constraint on the structure of strongly coupled, asymptotically free field theories. The constraint takes the form of an inequality limiting the number of degrees of freedom in the infrared description of a theory relative to the number of underlying, ultraviolet degrees of freedom. We apply the inequality to a variety of theories (both supersymmetric and nonsupersymmetric), where it agrees with all known results and leads to interesting new constraints on low energy spectra. We discuss the relation of this constraint to renormalization group c theorems. copyright 1999 The American Physical Society
Heat conduction in 2D strongly-coupled dusty plasmas
Hou, Lu-Jing
2008-01-01
We perform non-equilibrium simulations to study heat conduction in two-dimensional strongly coupled dusty plasmas. Temperature gradients are established by heating one part of the otherwise equilibrium system to a higher temperature. Heat conductivity is measured directly from the stationary temperature profile and heat flux. Particular attention is paid to the influence of damping effect on the heat conduction. It is found that the heat conductivity increases with the decrease of the damping rate, while its magnitude confirms previous experimental measurement.
Black hole thermodynamics from calculations in strongly coupled gauge theory.
Kabat, D; Lifschytz, G; Lowe, D A
2001-02-19
We develop an approximation scheme for the quantum mechanics of N D0-branes at finite temperature in the 't Hooft large- N limit. The entropy of the quantum mechanics calculated using this approximation agrees well with the Bekenstein-Hawking entropy of a ten-dimensional nonextremal black hole with 0-brane charge. This result is in accordance with the duality conjectured by Itzhaki, Maldacena, Sonnenschein, and Yankielowicz [Phys. Rev. D 58, 046004 (1998)]. Our approximation scheme provides a model for the density matrix which describes a black hole in the strongly coupled quantum mechanics. PMID:11290159
Mobility in a strongly coupled dusty plasma with gas
Liu, Bin; Goree, J.
2014-01-01
The mobility of a charged projectile in a strongly coupled dusty plasma is simulated. A net force $F$, opposed by a combination of collisional scattering and gas friction, causes projectiles to drift at a mobility-limited velocity $u_p$. The mobility $\\mu_p=u_p/F$ of the projectile's motion is obtained. Two regimes depending on $F$ are identified. In the high force regime, $\\mu_p \\propto F^{0.23}$, and the scattering cross section $\\sigma_s$ diminishes as $u_p^{-6/5}$. Results for $\\sigma_s$ ...
Hydraulic jumps in inhomogeneous strongly coupled toroidal dust flows
Piel, Alexander; Wilms, Jochen
2016-07-01
The inhomogeneous flow of strongly coupled dust particles in a toroidal particle trap with harmonic radial confinement is analyzed in the incompressible fluid limit. It is shown that the flow can spontaneously generate shock-like events, which are similar to the hydraulic jump in open channel flows. A definition of the Froude number for this model is given and the critical speed is recovered as the group velocity of surface waves. This hydraulic model is compared with molecular-dynamics simulations, which show that a sudden bifurcation of the flow lines and a localized temperature peak appear just at the point where the critical condition for the hydraulic jump is located.
Two universal results for Wilson loops at strong coupling
Hartnoll, Sean A.
2006-01-01
We present results for Wilson loops in strongly coupled gauge theories. The loops may be taken around an arbitrarily shaped contour and in any field theory with a dual IIB geometry of the form M x S^5. No assumptions about supersymmetry are made. The first result uses D5 branes to show how the loop in any antisymmetric representation is computed in terms of the loop in the fundamental representation. The second result uses D3 branes to observe that each loop defines a rich sequence of operato...
Laser enhanced transports in strongly coupled dusty plasmas
The stress induced microscopic responses of dust particles in strongly coupled dusty plasma liquids suspended in plasma traps are investigated experimentally. Narrow laser beams are used to generate stress on dust particles through optical pressure. Assisted by background thermal fluctuations, chaotic micro-vortices with decaying intensities from the laser beam are generated. The forward transport and transverse diffusion rate are enhanced and show nonlinear reponse to the external stress. Visco-elastic response is observed for an elongated liquid cluster driven by a periodically chopped laser beam. The shear wave is damped. (orig.)
Laser enhanced transports in strongly coupled dusty plasmas
Juan Wentau; Chang Minghua; Lai Yingju; Chen Mingheng; I Lin [National Central Univ., Chung-li (Taiwan). Physics Dept.
2001-07-01
The stress induced microscopic responses of dust particles in strongly coupled dusty plasma liquids suspended in plasma traps are investigated experimentally. Narrow laser beams are used to generate stress on dust particles through optical pressure. Assisted by background thermal fluctuations, chaotic micro-vortices with decaying intensities from the laser beam are generated. The forward transport and transverse diffusion rate are enhanced and show nonlinear reponse to the external stress. Visco-elastic response is observed for an elongated liquid cluster driven by a periodically chopped laser beam. The shear wave is damped. (orig.)
First and Second Law of Thermodynamics at Strong Coupling
Seifert, Udo
2016-01-01
For a small driven system coupled strongly to a heat bath, internal energy and exchanged heat are identified such that they obey the usual additive form of the first law. By identifying this exchanged heat with the entropy change of the bath, the total entropy production is shown to obey an integral fluctuation theorem on the trajectory level implying the second law in the form of a Clausius inequalilty on the ensemble level. In this Hamiltonian approach, the assumption of an initially uncorrelated state is not required. The conditions under which the proposed identification of heat is unique and experimentally accessible are clarified.
On the Classical Coupling between Gravity and Electromagnetism
Maria Becker; Adam Caprez; Herman Batelaan
2015-01-01
Coupling between electromagnetism and gravity, manifested as the distorted Coulomb field of a charge distribution in a gravitational field, has never been observed. A physical system consisting of an electron in a charged shell provides a coupling that is orders of magnitude stronger than for any previously-considered system. A shell voltage of one megavolt is required to establish a gravitationally-induced electromagnetic force equal in magnitude to the force of gravity on an electron. The ...
Thermalization and confinement in strongly coupled gauge theories
Ishii, Takaaki; Rosen, Christopher
2016-01-01
Quantum field theories of strongly interacting matter sometimes have a useful holographic description in terms of the variables of a gravitational theory in higher dimensions. This duality maps time dependent physics in the gauge theory to time dependent solutions of the Einstein equations in the gravity theory. In order to better understand the process by which "real world" theories such as QCD behave out of thermodynamic equilibrium, we study time dependent perturbations to states in a model of a confining, strongly coupled gauge theory via holography. Operationally, this involves solving a set of non-linear Einstein equations supplemented with specific time dependent boundary conditions. The resulting solutions allow one to comment on the timescale by which the perturbed states thermalize, as well as to quantify the properties of the final state as a function of the perturbation parameters. We comment on the influence of the dual gauge theory's confinement scale on these results, as well as the appearance ...
Heavy Quark Diffusion in Strongly Coupled Anisotropic Plasmas
Giataganas, Dimitrios
2013-01-01
We study the Langevin diffusion of a relativistic heavy quark in anisotropic strongly coupled theories in the local limit. Firstly, we use the axion space-dependent deformed anisotropic N=4 sYM, where the geometry anisotropy is always prolate, while the pressure anisotropy may be prolate or oblate. For motion along the anisotropic direction we find that the effective temperature for the quark can be larger than the heat bath temperature, in contrast to what happens in the isotropic theory. The longitudinal and transverse Langevin diffusion coefficients depend strongly on the anisotropy, the direction of motion and the transverse direction considered. We analyze the anisotropy effects to the coefficients and compare them to each other and to them of the isotropic theory. To examine the dependence of the coefficients on the type of the geometry, we consider another bottom-up anisotropic model. Changing the geometry from prolate to oblate, certain diffusion coefficients interchange their behaviors. In both aniso...
Strong-coupling approach to nematicity in the cuprates
Orth, Peter Philipp; Jeevanesan, Bhilahari; Schmalian, Joerg; Fernandes, Rafael
The underdoped cuprate superconductor YBa2Cu3O7-δ is known to exhibit an electronic nematic phase in proximity to antiferromagnetism. While nematicity sets in at large temperatures of T ~ 150 K, static spin density wave order only emerges at much lower temperatures. The magnetic response shows a strong in-plane anisotropy, displaying incommensurate Bragg peaks along one of the crystalline directions and a commensurate peak along the other one. Such an anisotropy persists even in the absence of long-range magnetic order at higher temperatures, marking the onset of nematic order. Here we theoretically investigate this situation using a strong-coupling method that takes into account both the localized Cu spins and the holes doped into the oxygen orbitals. We derive an effective spin Hamiltonian and show that charge fluctuations promote an enhancement of the nematic susceptibility near the antiferromagnetic transition temperature.
Berges, Jürgen; Rothkopf, Alexander; Schmidt, Jonas
2008-07-25
Strongly correlated systems far from equilibrium can exhibit scaling solutions with a dynamically generated weak coupling. We show this by investigating isolated systems described by relativistic quantum field theories for initial conditions leading to nonequilibrium instabilities, such as parametric resonance or spinodal decomposition. The nonthermal fixed points prevent fast thermalization if classical-statistical fluctuations dominate over quantum fluctuations. We comment on the possible significance of these results for the heating of the early Universe after inflation and the question of fast thermalization in heavy-ion collision experiments. PMID:18764319
Nonlinear Temporal Dynamics of Strongly Coupled Quantum Dot-Cavity System
Majumdar, Arka; Bajcsy, Michal; Vuckovic, Jelena
2011-01-01
We theoretically analyze and simulate the temporal dynamics of strongly coupled quantum dot-cavity system driven by a resonant laser pulse. We observe the signature of Rabi oscillation in the time resolved response of the system (i.e., in the numerically calculated cavity output), derive simplified linear and non-linear semi-classical models that approximate well the system's behavior in the limits of high and low power drive pulse, and describe the role of quantum coherence in the exact dynamics of the system. Finally, we also present experimental data showing the signature of the Rabi oscillation in time domain.
Neutron limit on the strongly-coupled chameleon field
Li, K.; Arif, M.; Cory, D. G.; Haun, R.; Heacock, B.; Huber, M. G.; Nsofini, J.; Pushin, D. A.; Saggu, P.; Sarenac, D.; Shahi, C. B.; Skavysh, V.; Snow, W. M.; Young, A. R.; Index Collaboration
2016-03-01
The physical origin of the dark energy that causes the accelerated expansion rate of the Universe is one of the major open questions of cosmology. One set of theories postulates the existence of a self-interacting scalar field for dark energy coupling to matter. In the chameleon dark energy theory, this coupling induces a screening mechanism such that the field amplitude is nonzero in empty space but is greatly suppressed in regions of terrestrial matter density. However measurements performed under appropriate vacuum conditions can enable the chameleon field to appear in the apparatus, where it can be subjected to laboratory experiments. Here we report the most stringent upper bound on the free neutron-chameleon coupling in the strongly coupled limit of the chameleon theory using neutron interferometric techniques. Our experiment sought the chameleon field through the relative phase shift it would induce along one of the neutron paths inside a perfect crystal neutron interferometer. The amplitude of the chameleon field was actively modulated by varying the millibar pressures inside a dual-chamber aluminum cell. We report a 95% confidence level upper bound on the neutron-chameleon coupling β ranging from β <4.7 ×106 for a Ratra-Peebles index of n =1 in the nonlinear scalar field potential to β <2.4 ×107 for n =6 , one order of magnitude more sensitive than the most recent free neutron limit for intermediate n . Similar experiments can explore the full parameter range for chameleon dark energy in the foreseeable future.
Classical nuclear motion coupled to electronic non-adiabatic transitions
Agostini, Federica; Abedi, Ali; Gross, E. K. U.
2014-12-01
Based on the exact factorization of the electron-nuclear wave function, we have recently proposed a mixed quantum-classical scheme [A. Abedi, F. Agostini, and E. K. U. Gross, Europhys. Lett. 106, 33001 (2014)] to deal with non-adiabatic processes. Here we present a comprehensive description of the formalism, including the full derivation of the equations of motion. Numerical results are presented for a model system for non-adiabatic charge transfer in order to test the performance of the method and to validate the underlying approximations.
Classical nuclear motion coupled to electronic non-adiabatic transitions
Agostini, Federica; Abedi, Ali; Gross, E. K. U. [Max-Planck Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Germany)
2014-12-07
Based on the exact factorization of the electron-nuclear wave function, we have recently proposed a mixed quantum-classical scheme [A. Abedi, F. Agostini, and E. K. U. Gross, Europhys. Lett. 106, 33001 (2014)] to deal with non-adiabatic processes. Here we present a comprehensive description of the formalism, including the full derivation of the equations of motion. Numerical results are presented for a model system for non-adiabatic charge transfer in order to test the performance of the method and to validate the underlying approximations.
Classical nuclear motion coupled to electronic non-adiabatic transitions
Based on the exact factorization of the electron-nuclear wave function, we have recently proposed a mixed quantum-classical scheme [A. Abedi, F. Agostini, and E. K. U. Gross, Europhys. Lett. 106, 33001 (2014)] to deal with non-adiabatic processes. Here we present a comprehensive description of the formalism, including the full derivation of the equations of motion. Numerical results are presented for a model system for non-adiabatic charge transfer in order to test the performance of the method and to validate the underlying approximations
Classical Kolmogorov scaling is inconsistent with local coupling
Uhlig, C
1996-01-01
We consider cascade models of turbulence which are obtained by restricting the Navier-Stokes equation to local interactions. By combining the results of the method of extended self-similarity and a novel subgrid model, we investigate the inertial range fluctuations of the cascade. Significant corrections to the classical scaling exponents are found. The dynamics of our local Navier-Stokes models is described accurately by a simple set of Langevin equations proposed earlier as a model of turbulence [Phys. Rev. E {\\bf 50}, 285 (1994)]. This allows for a prediction of the intermittency exponents without adjustable parameters. Excellent agreement with numerical simulations is found.
Quantum to Classical Transition in a System of Two Coupled Kicked Rotors
ZHAO Wen-Lei; JIE Quan-Lin
2009-01-01
We investigate the quantum-classical transition in a system of two coupled kicked rotors. We find that when the mass of one kicked rotor is much smaller than the other's, the influence of the light kicked rotor is still able to make decoherence of the heavy one. This leads to the quantum-classical transition of the heavy kicked rotor. We demonstrate this by two different coupling potentials.
Classical Monte-Carlo simulation for Rydberg states ionization in strong field
Carrat, Vincent; Magnuson, Eric; Gallagher, Thomas
2016-05-01
The resilience of Rydberg states against ionization has fascinated physicists for a long time. One might expect that the loosely bound electron would be ionized by modest electromagnetic field. However, experiments show that a notable fraction of neutral atoms survive in Rydberg states when exposed to strong microwave or laser fields. Energy transfer between the field and the photoelectron occurs when the electron is close to the ionic core and depends on the phase of the field. Since those states have orbital times that can be larger than the field pulse duration, these energy exchanges will only occur a few times. While we can experimentally control the initial time when we create the Rydberg states and as a consequence the initial energy transfer from the field, our classical calculation suggests that the phase when the electron is returning to the ionic core on the next orbit is chaotic. Statistically the electron only has a 50% chance to gain energy which may lead to ionization. Additionally the population tends to accumulate in very high n states where ionization is less likely due to fewer rescattering events. Though incomplete, this classical Monte-Carlo simulation provides useful insights for understanding the experimental observations. This work has been entirely performed at University of Virginia and is supported by the U. S. Department of Energy, Office of Basic energy Sciences.
The strong coupling regime of twelve flavors QCD
da Silva, Tiago Nunes
2012-01-01
We summarize the results recently reported in Ref.[1] [A. Deuzeman, M.P. Lombardo, T. Nunes da Silva and E. Pallante,"The bulk transition of QCD with twelve flavors and the role of improvement"] for the SU(3) gauge theory with Nf=12 fundamental flavors, and we add some numerical evidence and theoretical discussion. In particular, we study the nature of the bulk transition that separates a chirally broken phase at strong coupling from a chirally restored phase at weak coupling. When a non-improved action is used, a rapid crossover is observed at small bare quark masses. Our results confirm a first order nature for this transition, in agreement with previous results we obtained using an improved action. As shown in Ref.[1], when improvement of the action is used, the transition is preceded by a second rapid crossover at weaker coupling and an exotic phase emerges, where chiral symmetry is not yet broken. This can be explained [1] by the non hermiticity of the improved lattice Transfer matrix, arising from the c...
Mesoscopic Anderson Box: Connecting Weak to Strong Coupling
Liu, Dong E.; Burdin, Sebastien; Baranger, Harold U.; Ullmo, Denis
2011-03-01
Both the weakly coupled and strong coupling Anderson impurity problem are characterized by a Fermi-liquid theory with weakly interacting quasiparticles. In an Anderson box, mesoscopic fluctuations of the effective single particle properties will be large. We study how the statistical fluctuations in these two problems are connected. We use random matrix theory and the slave boson mean field approximation (SBMF, at low temperature) to address this question, obtaining the following results. First, for a resonant level model such as results from the SBMF approximation, we find the joint distribution of energy levels with and without the resonant level present. Second, if only energy levels within the Kondo resonance are considered, the distribution of perturbed levels collapse to one universal form for both GOE and GUE for all values of the coupling V. Finally, a purely Fermi liquid method is developed for calculating the perturbed levels within the Kondo resonance. Comparing the levels that result to those of the SBMF, we find remarkable agreement.
The strong coupling constant of QCD with four flavors
Tekin, Fatih
2010-11-01
In this thesis we study the theory of strong interaction Quantum Chromodynamics on a space-time lattice (lattice QCD) with four flavors of dynamical fermions by numerical simulations. In the early days of lattice QCD, only pure gauge field simulations were accessible to the computational facilities and the effects of quark polarization were neglected. The so-called fermion determinant in the path integral was set to one (quenched approximation). The reason for this approximation was mainly the limitation of computational power because the inclusion of the fermion determinant required an enormous numerical effort. However, for full QCD simulations the virtual quark loops had to be taken into account and the development of new machines and new algorithmic techniques made the so-called dynamical simulations with at least two flavors possible. In recent years, different collaborations studied lattice QCD with dynamical fermions. In our project we study lattice QCD with four degenerated flavors of O(a) improved Wilson quarks in the Schroedinger functional scheme and calculate the energy dependence of the strong coupling constant. For this purpose, we determine the O(a) improvement coefficient c{sub sw} with four flavors and use this result to calculate the step scaling function of QCD with four flavors which describes the scale evolution of the running coupling. Using a recursive finite-size technique, the {lambda} parameter is determined in units of a technical scale L{sub max} which is an unambiguously defined length in the hadronic regime. The coupling {alpha}{sub SF} of QCD in the so-called Schroedinger functional scheme is calculated over a wide range of energies non-perturbatively and compared with 2-loop and 3-loop perturbation theory as well as with the non-perturbative result for only two flavors. (orig.)
Strongly coupled inorganic/nanocarbon hybrid materials for advanced electrocatalysis.
Liang, Yongye; Li, Yanguang; Wang, Hailiang; Dai, Hongjie
2013-02-13
Electrochemical systems, such as fuel cell and water splitting devices, represent some of the most efficient and environmentally friendly technologies for energy conversion and storage. Electrocatalysts play key roles in the chemical processes but often limit the performance of the entire systems due to insufficient activity, lifetime, or high cost. It has been a long-standing challenge to develop efficient and durable electrocatalysts at low cost. In this Perspective, we present our recent efforts in developing strongly coupled inorganic/nanocarbon hybrid materials to improve the electrocatalytic activities and stability of inorganic metal oxides, hydroxides, sulfides, and metal-nitrogen complexes. The hybrid materials are synthesized by direct nucleation, growth, and anchoring of inorganic nanomaterials on the functional groups of oxidized nanocarbon substrates including graphene and carbon nanotubes. This approach affords strong chemical attachment and electrical coupling between the electrocatalytic nanoparticles and nanocarbon, leading to nonprecious metal-based electrocatalysts with improved activity and durability for the oxygen reduction reaction for fuel cells and chlor-alkali catalysis, oxygen evolution reaction, and hydrogen evolution reaction. X-ray absorption near-edge structure and scanning transmission electron microscopy are employed to characterize the hybrids materials and reveal the coupling effects between inorganic nanomaterials and nanocarbon substrates. Z-contrast imaging and electron energy loss spectroscopy at single atom level are performed to investigate the nature of catalytic sites on ultrathin graphene sheets. Nanocarbon-based hybrid materials may present new opportunities for the development of electrocatalysts meeting the requirements of activity, durability, and cost for large-scale electrochemical applications. PMID:23339685
Bogdanov, O V
2014-01-01
The relations among the components of the exit momenta of ultrarelativistic electrons scattered on a strong electromagnetic wave of a low (optical) frequency and linear polarization are established using the exact solutions to the equations of motion with radiation reaction included (the Landau-Lifshitz equation). It is found that the momentum components of the electrons traversed the electromagnetic wave depend weakly on the initial values of the momenta. These electrons are mostly scattered at the small angles to the direction of propagation of the electromagnetic wave. The maximum Lorentz factor of the electrons crossed the electromagnetic wave is proportional to the work done by the electromagnetic field and is independent of the initial momenta. The momentum component parallel to the electric field strength vector of the electromagnetic wave is determined only by the diameter of the laser beam measured in the units of the classical electron radius. As for the reflected electrons, they for the most part l...
A ''geometric'' derivation of the strong coupling constant
Since more than a decade, a bi-scale, unified approach to strong and gravitational interactions has been proposed, that uses the geometrical methods of general relativity, and yielded results similar to ''strong gravity'' theory's. We fix our attention, in this note, on hadron structure, and show that also the strong interaction strength αS, ordinarily called the ''(perturbative) coupling-constant square'', can be evaluated within our theory, and found to decrease (increase) as the ''distance'' r decreases (increases). This yields both the confinement of the hadron constituents (for large values of r), and their asymptotic freedom (for small values of r inside the hadron): in qualitative agreement with the experimental evidence. In other words, our approach leads us, on a purely theoretical ground, to a dependence of αS on r which had been previously found only on phenomenological and heuristic grounds. We expect the above agreement to be also quantitative, on the basis of a few checks performed in this paper, and of further work of ours about calculating meson mass-spectra. (author). 10 refs
Classical and quantum modes of coupled Mathieu equations
Landa, H.; Reznik, B.; Drewsen, M.;
2012-01-01
We expand the solutions of linearly coupled Mathieu equations in terms of infinite-continued matrix inversions, and use it to find the modes which diagonalize the dynamical problem. This allows obtaining explicitly the (Floquet–Lyapunov) transformation to coordinates in which the motion is that o...... general linear systems with periodic coefficients (coupled Hill equations, periodically driven parametric oscillators), and to nonlinear systems as a starting point for convenient perturbative treatment of the nonlinearity....... decoupled linear oscillators. We use this transformation to solve the Heisenberg equations of the corresponding quantum-mechanical problem, and find the quantum wavefunctions for stable oscillations, expressed in configuration space. The obtained transformation and quantum solutions can be applied to more......We expand the solutions of linearly coupled Mathieu equations in terms of infinite-continued matrix inversions, and use it to find the modes which diagonalize the dynamical problem. This allows obtaining explicitly the (Floquet–Lyapunov) transformation to coordinates in which the motion is that of...
Mode imaging and selection in strongly coupled nanoantennas
Huang, Jer-Shing; Geisler, Peter; Weinmann, Pia; Kamp, Martin; Forchel, Alfred; Biagioni, Paolo; Hecht, Bert
2010-01-01
The number of eigenmodes in plasmonic nanostructures increases with complexity due to mode hybridization, raising the need for efficient mode characterization and selection. Here we experimentally demonstrate direct imaging and selective excitation of the bonding and antibonding plasmon mode in symmetric dipole nanoantennas using confocal two-photon photoluminescence mapping. Excitation of a high-quality-factor antibonding resonance manifests itself as a two-lobed pattern instead of the single spot observed for the broad bonding resonance, in accordance with numerical simulations. The two-lobed pattern is observed due to the fact that excitation of the antibonding mode is forbidden for symmetric excitation at the feedgap, while concomitantly the mode energy splitting is large enough to suppress excitation of the bonding mode. The controlled excitation of modes in strongly coupled plasmonic nanostructures is mandatory for efficient sensors, in coherent control as well as for implementing well-defined functiona...
Thermodynamics of the BMN matrix model at strong coupling
Costa, Miguel S.; Greenspan, Lauren; Penedones, João; Santos, Jorge E.
2015-03-01
We construct the black hole geometry dual to the deconfined phase of the BMN matrix model at strong 't Hooft coupling. We approach this solution from the limit of large temperature where it is approximately that of the non-extremal D0-brane geometry with a spherical S 8 horizon. This geometry preserves the SO(9) symmetry of the matrix model trivial vacuum. As the temperature decreases the horizon becomes deformed and breaks the SO(9) to the SO(6) × SO(3) symmetry of the matrix model. When the black hole free energy crosses zero the system undergoes a phase transition to the confined phase described by a Lin-Maldacena geometry. We determine this critical temperature, whose computation is also within reach of Monte Carlo simulations of the matrix model.
Thermodynamics of the BMN matrix model at strong coupling
Costa, Miguel S; Penedones, Joao; Santos, Jorge
2014-01-01
We construct the black hole geometry dual to the deconfined phase of the BMN matrix model at strong 't Hooft coupling. We approach this solution from the limit of large temperature where it is approximately that of the non-extremal D0-brane geometry with a spherical $S^8$ horizon. This geometry preserves the $SO(9)$ symmetry of the matrix model trivial vacuum. As the temperature decreases the horizon becomes deformed and breaks the $SO(9)$ to the $SO(6)\\times SO(3)$ symmetry of the matrix model. When the black hole free energy crosses zero the system undergoes a phase transition to the confined phase described by a Lin-Maldacena geometry. We determine this critical temperature, whose computation is also within reach of Monte Carlo simulations of the matrix model.
Anomaly induced transport coefficients, from weak to strong coupling
Pena-Benitez, Francisco
2013-01-01
The existence of new transport phenomena associated to the presence of quantum anomalies has atracted very recently the attention of theorist. These transport coefficient have very interesting properties, for example, they do not renormalize. The most famous case of anomaly induced transport phenomena is the Chiral Magnetic Effect, in which an electric current is produced by a magnetic field if the system has a different number of right handed fermions respect the left handed one. In this thesis we have studied those transport coefficients from Kubo formulas at weak and strong coupling. To finish a fluid/gravity approach is used to compute all the second order anomalous coefficients in an anomalous conformal fluid.
Supernova neutrinos: Strong coupling effects of weak interactions
Fogli, G L; Marrone, A; Mirizzi, A
2008-01-01
In core-collapse supernovae, neutrinos and antineutrinos are initially subject to significant self-interactions induced by weak neutral currents, which may induce strong-coupling effects on the flavor evolution (collective transitions). The interpretation of the effects is simplified when self-induced collective transitions are decoupled from ordinary matter oscillations, as for the matter density profile that we discuss. In this case, approximate analytical tools can be used (pendulum analogy, swap of energy spectra). For inverted neutrino mass hierarchy, the sequence of effects involves: synchronization, bipolar oscillations, and spectral split. Our simulations shows that the main features of these regimes are not altered when passing from simplified (angle-averaged) treatments to full, multi-angle numerical experiments.
On the flavor problem in strongly coupled theories
This thesis is on the flavor problem of Randall Sundrum models and their strongly coupled dual theories. These models are particularly well motivated extensions of the Standard Model, because they simultaneously address the gauge hierarchy problem and the hierarchies in the quark masses and mixings. In order to put this into context, special attention is given to concepts underlying the theories which can explain the hierarchy problem and the flavor structure of the Standard Model (SM). The AdS/CFT duality is introduced and its implications for the Randall Sundrum model with fermions in the bulk and general bulk gauge groups is investigated. It is shown that the different terms in the general 5D propagator of a bulk gauge field can be related to the corresponding diagrams of the strongly coupled dual, which allows for a deeper understanding of the origin of flavor changing neutral currents generated by the exchange of the Kaluza Klein excitations of these bulk fields. In the numerical analysis, different observables which are sensitive to corrections from the tree-level exchange of these resonances will be presented on the basis of updated experimental data from the Tevatron and LHC experiments. This includes electroweak precision observables, namely corrections to the S and T parameters followed by corrections to the Zb anti b vertex, flavor changing observables with flavor changes at one vertex, viz. B(Bd→μ+μ-) and B(Bs→μ+μ-), and two vertices, viz. Sψφ and vertical stroke εK vertical stroke, as well as bounds from direct detection experiments. The analysis will show that all of these bounds can be brought in agreement with a new physics scale ΛNP in the TeV range, except for the CP violating quantity vertical stroke εK vertical stroke, which requires ΛNP=O(10) TeV in the absence of fine-tuning. The numerous modifications of the Randall Sundrum model in the literature, which try to attenuate this bound are reviewed and categorized. Subsequently, a
On the flavor problem in strongly coupled theories
Bauer, Martin
2012-11-28
This thesis is on the flavor problem of Randall Sundrum models and their strongly coupled dual theories. These models are particularly well motivated extensions of the Standard Model, because they simultaneously address the gauge hierarchy problem and the hierarchies in the quark masses and mixings. In order to put this into context, special attention is given to concepts underlying the theories which can explain the hierarchy problem and the flavor structure of the Standard Model (SM). The AdS/CFT duality is introduced and its implications for the Randall Sundrum model with fermions in the bulk and general bulk gauge groups is investigated. It is shown that the different terms in the general 5D propagator of a bulk gauge field can be related to the corresponding diagrams of the strongly coupled dual, which allows for a deeper understanding of the origin of flavor changing neutral currents generated by the exchange of the Kaluza Klein excitations of these bulk fields. In the numerical analysis, different observables which are sensitive to corrections from the tree-level exchange of these resonances will be presented on the basis of updated experimental data from the Tevatron and LHC experiments. This includes electroweak precision observables, namely corrections to the S and T parameters followed by corrections to the Zb anti b vertex, flavor changing observables with flavor changes at one vertex, viz. B(B{sub d}{yields}{mu}{sup +}{mu}{sup -}) and B(B{sub s}{yields}{mu}{sup +}{mu}{sup -}), and two vertices, viz. S{sub {psi}{phi}} and vertical stroke {epsilon}{sub K} vertical stroke, as well as bounds from direct detection experiments. The analysis will show that all of these bounds can be brought in agreement with a new physics scale {Lambda}{sub NP} in the TeV range, except for the CP violating quantity vertical stroke {epsilon}{sub K} vertical stroke, which requires {Lambda}{sub NP}=O(10) TeV in the absence of fine-tuning. The numerous modifications of the
The properties of strong couple bound polaron in monolayer graphene
Ding, Zhao-Hua; Zhao, Ying; Xiao, Jing-Lin
2016-09-01
Based on the Hamiltonian of the interaction energy between electron on the surface of the graphene and longitudinal acoustic phonon on the surface of the substrate, the paper studies the properties of strong couple polaron in monolayer graphene considering the coulomb doping problem. The conventional Lee-Low-Pine unitary transformation method and linear combination operator method are used to calculate the ground state energy of the polaron. The results show that the ground state energy of the system has a linear relationship with the magnetic field strength, the cut-off wave number, the coulomb bound parameter, the distance between the graphene and the substrates, meanwhile, the ground state energy will split into two branches near the Dirac point.
Mathematical structure of Rabi oscillations in the strong coupling regime
In this paper, we generalize the Jaynes-Cummings Hamiltonian by making use of some operators based on Lie algebras su(1, 1) and su(2), and study a mathematical structure of Rabi floppings of these models in the strong coupling regime. We show that Rabi frequencies are given by matrix elements of generalized coherent operators (Fujii K 2002 Preprint quant-ph/0202081) under the rotating-wave approximation. In the first half, we make a general review of coherent operators and generalized coherent ones based on Lie algebras su(1, 1) and su(2). In the latter half, we carry out a detailed examination of Frasca (Frasca M 2001 Preprint quant-ph/0111134) and generalize his method, and moreover present some related problems. We also apply our results to the construction of controlled unitary gates in quantum computation. Lastly, we make a brief comment on application to holonomic quantum computation
Strongly coupled copper plasma generated by underwater electrical wire explosion
A number of theoretical approaches to the analysis of the parameters of a discharge channel consisting of strongly coupled plasma generated in the process of underwater electrical wire explosion are presented. The analysis is based on experimental results obtained from discharges employing Cu wire. The obtained experimental data included electrical measurements and optical observations from which information about the dynamics of the water flow was extrapolated. Numerical calculation based on a 1D magnetohydrodynamic model was used to simulate the process of underwater wire explosion. A wide range conductivity model was applied in this calculation and good agreement with a set of experimental data was obtained. A method of determining the average temperature of the discharge channel based on this model and experimental results is proposed, and the limits of this method's applicability are discussed
Strongly coupled gauge theories: What can lattice calculations teach us?
Hasenfratz, A; Rebbi, C; Weinberg, E; Witzel, O
2015-01-01
The dynamical origin of electroweak symmetry breaking is an open question with many possible theoretical explanations. Strongly coupled systems predicting the Higgs boson as a bound state of a new gauge-fermion interaction form one class of candidate models. Due to increased statistics, LHC run II will further constrain the phenomenologically viable models in the near future. In the meanwhile it is important to understand the general properties and specific features of the different competing models. In this work we discuss many-flavor gauge-fermion systems that contain both massless (light) and massive fermions. The former provide Goldstone bosons and trigger electroweak symmetry breaking, while the latter indirectly influence the infrared dynamics. Numerical results reveal that such systems can exhibit a light $0^{++}$ isosinglet scalar, well separated from the rest of the spectrum. Further, when we set the scale via the $vev$ of electroweak symmetry breaking, we predict a 2 TeV vector resonance which could...
Strong-coupling effects in a plasma of confining gluons
Florkowski, Wojciech; Su, Nan; Tywoniuk, Konrad
2015-01-01
The plasma consisting of confining gluons resulting from the Gribov quantization of the SU(3) Yang-Mills theory is studied using non-equilibrium fluid dynamical framework. Exploiting the Bjorken symmetry and using linear response theory a general analytic expressions for the bulk and shear viscosity coefficients are derived. It is found that the considered system exhibits a number of properties similar to the strongly-coupled theories, where the conformality is explicitly broken. In particular, it is shown that, in the large temperature limit, bulk to shear viscosity ratio, scales linearly with the difference $1/3 - c_s^2$, where $c_s$ is the speed of sound. Results obtained from the analysis are in line with the interpretation of the quark-gluon plasma as an almost perfect fluid.
Strongly coupled semiclassical plasma: interaction model and some properties
In the report a fully ionized strongly coupled hydrogen plasma is considered. The density number is considered within range n=ne=ni≅(1021-2·1025)sm-3, and the temperature domian is T≅(5·104-106) K. The coupling parameter Γ is defined by Γ=e2/αkBT, where kB is the Boltzmann constant and e is electrical charge, α=(3/4πn)1/3 is the average distance between the particles (Wigner-Seitz radius). The dimensionless density parameter rs=α/αB is given in terms of the Bohr radius αB=ℎ2/me2∼0.529·10-8 sm. The degeneracy parameter for the electron was defined by the ratio between the thermal energy kBT and the Fermi energy EF:Θ=kBT/EF∼0.54·rs/Γ. The intermediate temperature-density region, where Γ≥1; Θ≅1; T>13.6 eV is examined. A semiclassical effective potential which account for the short-range, quantum diffraction and symmetry effects of charge carriers screening
Coupling of strongly localized graphene plasmons to molecular vibrations
Farmer, Damon; Li, Yilei; Yan, Hugen; Meng, Xiang; Zhu, Wenjuan; Osgood, Richard; Heinz, Tony; Avouris, Phaedon
2015-03-01
In this paper, we first present a determination of the out-of-plane confinement of the plasmons in graphene nanoribbons. Using light with a free-space wavelength of ~ 6 μ m, we excite plasmons in graphene nanoribbons that are ~ 100 nm wide. A red-shift in the plasmon frequency is induced by a thin layer of Poly (methyl methacrylate) (PMMA) adsorbed onto the nanoribbons surface due to dielectric screening effect. With increasing thickness of the PMMA layer, we observe a saturation of the frequency shift, from which we deduce an out-of-plane field plasmon field decay length of ~ 10 nm. The strongly confined plasmons in graphene produce significant enhancement of the field intensity. We show that this enhancement strengthens the coupling of graphene plasmon to vibrations in the PMMA molecules. The enhanced interaction is manifested through induced transparency in the graphene plasmon optical response when the plasmon and the vibrational frequencies are matched. We also show that this coupling is of an electromagnetic nature by comparing the evolution of the line shape as a function of the detuning of the two frequencies to simulations using the finite-difference time-domain method.
Using classical molecular dynamics (MD) simulations, we report on the development and propagation of a nonlinear heat front in parallel shear flows of a strongly coupled Yukawa liquid. At a given coupling strength, a subsonic shear profile is superposed on an equilibrated Yukawa liquid and Kelvin Helmholtz (KH) instability is observed. Coherent vortices are seen to emerge towards the nonlinear regime of the instability. It is seen that while inverse cascade leads to a continuous transfer of flow energy towards the largest scales, there is also a simultaneous transfer of flow energy into the thermal velocities of grains at the smallest scale. The latter is an effect of velocity shear and thus leads to the generation of a nonlinear heat front. In the linear regime, the heat front is seen to propagate at speed much lesser than the adiabatic sound speed of the liquid. Spatio-temporal growth of this heat front occurs concurrently with the inverse cascade of KH modes.
Ashwin, J.; Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382428, Gujarat (India)
2011-08-15
Using classical molecular dynamics (MD) simulations, we report on the development and propagation of a nonlinear heat front in parallel shear flows of a strongly coupled Yukawa liquid. At a given coupling strength, a subsonic shear profile is superposed on an equilibrated Yukawa liquid and Kelvin Helmholtz (KH) instability is observed. Coherent vortices are seen to emerge towards the nonlinear regime of the instability. It is seen that while inverse cascade leads to a continuous transfer of flow energy towards the largest scales, there is also a simultaneous transfer of flow energy into the thermal velocities of grains at the smallest scale. The latter is an effect of velocity shear and thus leads to the generation of a nonlinear heat front. In the linear regime, the heat front is seen to propagate at speed much lesser than the adiabatic sound speed of the liquid. Spatio-temporal growth of this heat front occurs concurrently with the inverse cascade of KH modes.
Quantum Thermodynamics in Strong Coupling: Heat Transport and Refrigeration
Gil Katz
2016-05-01
Full Text Available The performance characteristics of a heat rectifier and a heat pump are studied in a non-Markovian framework. The device is constructed from a molecule connected to a hot and cold reservoir. The heat baths are modelled using the stochastic surrogate Hamiltonian method. The molecule is modelled by an asymmetric double-well potential. Each well is semi-locally connected to a heat bath composed of spins. The dynamics are driven by a combined system–bath Hamiltonian. The temperature of the baths is regulated by a secondary spin bath composed of identical spins in thermal equilibrium. A random swap operation exchange spins between the primary and secondary baths. The combined system is studied in various system–bath coupling strengths. In all cases, the average heat current always flows from the hot towards the cold bath in accordance with the second law of thermodynamics. The asymmetry of the double well generates a rectifying effect, meaning that when the left and right baths are exchanged the heat current follows the hot-to-cold direction. The heat current is larger when the high frequency is coupled to the hot bath. Adding an external driving field can reverse the transport direction. Such a refrigeration effect is modelled by a periodic driving field in resonance with the frequency difference of the two potential wells. A minimal driving amplitude is required to overcome the heat leak effect. In the strong driving regime the cooling power is non-monotonic with the system–bath coupling.
Intrinsic decoherence and classical-quantum correspondence in two coupled delta-kicked rotors
Park, Hwa-Kyun; Kim, Sang Wook
2002-01-01
We show that classical-quantum correspondence of center of mass motion in two coupled delta-kicked rotors can be obtained from intrinsic decoherence of the system itself which occurs due to the entanglement of the center of mass motion to the internal degree of freedom without coupling to external environment.
Energy exchange in strongly coupled plasmas with electron drift
Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz (Iran, Islamic Republic of); International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany); Ghorbanalilu, M. [Physics Department, Shahid Beheshti University, G.C., Evin, Tehran (Iran, Islamic Republic of)
2015-11-15
In this paper, the generalized viscoelastic collisional quantum hydrodynamic model is employed in order to investigate the linear dielectric response of a quantum plasma in the presence of strong electron-beam plasma interactions. The generalized Chandrasekhar's relativistic degeneracy pressure together with the electron-exchange and Coulomb interaction effects are taken into account in order to extend current research to a wide range of plasma number density relevant to big planetary cores and astrophysical compact objects. The previously calculated shear viscosity and the electron-ion collision frequencies are used for strongly coupled ion fluid. The effect of the electron-beam velocity on complex linear dielectric function is found to be profound. This effect is clearly interpreted in terms of the wave-particle interactions and their energy-exchange according to the sign of the imaginary dielectric function, which is closely related to the wave attenuation coefficient in plasmas. Such kinetic effect is also shown to be in close connection with the stopping power of a charged-particle beam in a quantum plasma. The effect of many independent plasma parameters, such as the ion charge-state, electron beam-velocity, and relativistic degeneracy, is shown to be significant on the growing/damping of plasma instability or energy loss/gain of the electron-beam.
Energy exchange in strongly coupled plasmas with electron drift
In this paper, the generalized viscoelastic collisional quantum hydrodynamic model is employed in order to investigate the linear dielectric response of a quantum plasma in the presence of strong electron-beam plasma interactions. The generalized Chandrasekhar's relativistic degeneracy pressure together with the electron-exchange and Coulomb interaction effects are taken into account in order to extend current research to a wide range of plasma number density relevant to big planetary cores and astrophysical compact objects. The previously calculated shear viscosity and the electron-ion collision frequencies are used for strongly coupled ion fluid. The effect of the electron-beam velocity on complex linear dielectric function is found to be profound. This effect is clearly interpreted in terms of the wave-particle interactions and their energy-exchange according to the sign of the imaginary dielectric function, which is closely related to the wave attenuation coefficient in plasmas. Such kinetic effect is also shown to be in close connection with the stopping power of a charged-particle beam in a quantum plasma. The effect of many independent plasma parameters, such as the ion charge-state, electron beam-velocity, and relativistic degeneracy, is shown to be significant on the growing/damping of plasma instability or energy loss/gain of the electron-beam
Nonlinear Debye screening in strongly-coupled plasmas
Sarmah, D; Tessarotto, M
2006-01-01
An ubiquitous property of plasmas is the so-called Debye shielding of the electrostatic potential. Important aspects of Debye screening concern, in particular, the investigation of non-linear charge screening effects taking place in strongly-coupled plasmas, that imply a reduction of the effective charge characterizing the Debye-H\\"{u}ckel potential. These effects are particularly relevant in dusty plasmas which are characterized by high-Z particles. The investigation of the effective interactions of these particles has attracted interest in recent years especially for numerical simulations. In this work we intend to analyze the consistency of the traditional mathematical model for the Debye screening. In particular, we intend to prove that the 3D Poisson equation involved in the DH model does not admit strong solutions. For this purpose a modified model is proposed which takes into account the effect of local plasma sheath (i.e., the local domain near test particles where the plasma must be considered discre...
Energy exchange in strongly coupled plasmas with electron drift
Akbari-Moghanjoughi, M.; Ghorbanalilu, M.
2015-11-01
In this paper, the generalized viscoelastic collisional quantum hydrodynamic model is employed in order to investigate the linear dielectric response of a quantum plasma in the presence of strong electron-beam plasma interactions. The generalized Chandrasekhar's relativistic degeneracy pressure together with the electron-exchange and Coulomb interaction effects are taken into account in order to extend current research to a wide range of plasma number density relevant to big planetary cores and astrophysical compact objects. The previously calculated shear viscosity and the electron-ion collision frequencies are used for strongly coupled ion fluid. The effect of the electron-beam velocity on complex linear dielectric function is found to be profound. This effect is clearly interpreted in terms of the wave-particle interactions and their energy-exchange according to the sign of the imaginary dielectric function, which is closely related to the wave attenuation coefficient in plasmas. Such kinetic effect is also shown to be in close connection with the stopping power of a charged-particle beam in a quantum plasma. The effect of many independent plasma parameters, such as the ion charge-state, electron beam-velocity, and relativistic degeneracy, is shown to be significant on the growing/damping of plasma instability or energy loss/gain of the electron-beam.
Kolmogorov flow in two dimensional strongly coupled dusty plasma
Gupta, Akanksha; Ganesh, R., E-mail: ganesh@ipr.res.in; Joy, Ashwin [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 382 428 (India)
2014-07-15
Undriven, incompressible Kolmogorov flow in two dimensional doubly periodic strongly coupled dusty plasma is modelled using generalised hydrodynamics, both in linear and nonlinear regime. A complete stability diagram is obtained for low Reynolds numbers R and for a range of viscoelastic relaxation time τ{sub m} [0 < τ{sub m} < 10]. For the system size considered, using a linear stability analysis, similar to Navier Stokes fluid (τ{sub m} = 0), it is found that for Reynolds number beyond a critical R, say R{sub c}, the Kolmogorov flow becomes unstable. Importantly, it is found that R{sub c} is strongly reduced for increasing values of τ{sub m}. A critical τ{sub m}{sup c} is found above which Kolmogorov flow is unconditionally unstable and becomes independent of Reynolds number. For R < R{sub c}, the neutral stability regime found in Navier Stokes fluid (τ{sub m} = 0) is now found to be a damped regime in viscoelastic fluids, thus changing the fundamental nature of transition of Kolmogorov flow as function of Reynolds number R. A new parallelized nonlinear pseudo spectral code has been developed and is benchmarked against eigen values for Kolmogorov flow obtained from linear analysis. Nonlinear states obtained from the pseudo spectral code exhibit cyclicity and pattern formation in vorticity and viscoelastic oscillations in energy.
Strongly coupled non-Abelian plasmas in a magnetic field
Critelli, Renato
2016-01-01
In this dissertation we use the gauge/gravity duality approach to study the dynamics of strongly coupled non-Abelian plasmas. Ultimately, we want to understand the properties of the quark-gluon plasma (QGP), whose scientifc interest by the scientific community escalated exponentially after its discovery in the 2000's through the collision of ultrarelativistic heavy ions. One can enrich the dynamics of the QGP by adding an external field, such as the baryon chemical potential (needed to study the QCD phase diagram), or a magnetic field. In this dissertation, we choose to investigate the magnetic effects. Indeed, there are compelling evidences that strong magnetic fields of the order $eB\\sim 10 m_\\pi^2$ are created in the early stages of ultrarelativistic heavy ion collisions. The chosen observable to scan possible effects of the magnetic field on the QGP was the viscosity, due to the famous result $\\eta/s=1/4\\pi$ obtained via holography. In a first approach we use a caricature of the QGP, the $\\mathcal{N}=4$ s...
Cubic Single Crystal Representations in Classical and Size-dependent Couple Stress Elasticity
Bansal, Dipanshu; Aref, Amjad J; Hadjesfandiari, Ali R
2015-01-01
Beginning with Cosserat theory in the early 20th century, there have been several different formulations for size-dependent elastic response. In this paper, we concentrate on the application of classical Cauchy theory and the recent parsimonious consistent couple stress theory to model a homogeneous linear elastic solid, exemplified by a pure single crystal with cubic structure. The focus is on an examination of elastodynamic response based upon wave velocities from ultrasonic excitation and phonon dispersion curves, along with adiabatic bulk moduli measurements. In particular, we consider in detail elastic parameter estimation within classical elasticity and consistent couple stress theory for four different cubic single crystals (NaCl, KCl, Cu, CuZn). The classical theory requires the estimation of three independent material parameters, while only one additional parameter relating skew-symmetric mean curvature to skew-symmetric couple-stress is needed for the size-dependent consistent couple stress theory. ...
Dynamics of an electron spin in strong classical and quantized electromagnetic fields
Skoromnik, Oleg
2014-07-09
The electron motion in the presence of a strong classical and quantized pulse of an electromagnetic field is studied with a special emphasis on the spin degree of freedom. It is shown that the Hamiltonian of this system can be separated into two parts with the help of canonical transformations of the field variables, namely the interaction between an electron and a single collective mode of the field and fluctuations relatively to this collective mode. The application of perturbation theory to the fluctuations allows the conditions of applicability of the single-mode approximation for the quantized external field to be formulated. Furthermore, within this approximation the electron spin evolution is investigated. In addition to fast spin oscillations at the laser frequency, a second time scale is identified due to the intensity-dependent emissions and absorptions of field quanta, that is collapse and revival dynamics. The effect is observable at the experimentally feasible intensity of 10{sup 18} Wcm{sup 2}. After this, we switch to the regime of higher intensities, when the fluctuations of the external field can be neglected. We investigate the asymmetries in the electron scattering arising due to the electron polarization and pulse duration, and constrain the optimal conditions for the asymmetry observation.
A coupled-trajectory quantum-classical approach to decoherence in non-adiabatic processes
Min, Seung Kyu; Gross, E K U
2015-01-01
We present a novel quantum-classical approach to non-adiabatic dynamics, deduced from the coupled electronic and nuclear equations in the framework of the exact factorization of the electron-nuclear wave function. The method is based on the quasi-classical interpretation of the nuclear wave function, whose phase is related to the classical momentum and whose density is represented in terms of classical trajectories. In this approximation, electronic decoherence is naturally induced as effect of the coupling to the nuclei and correctly reproduces the expected quantum behaviour. Moreover, the splitting of the nuclear wave packet is captured as consequence of the correct approximation of the time-dependent potential of the theory. This new approach offers a clear improvement over Ehrenfest-like dynamics. The theoretical derivation presented in the Letter is supported by numerical results that are compared to quantum mechanical calculations.
Effects of Strong Electronic Coupling in Chlorin and Bacteriochlorin Dyads.
Kang, Hyun Suk; Esemoto, Nopondo N; Diers, James R; Niedzwiedzki, Dariusz M; Greco, Jordan A; Akhigbe, Joshua; Yu, Zhanqian; Pancholi, Chirag; Bhagavathy, Ganga Viswanathan; Nguyen, Jamie K; Kirmaier, Christine; Birge, Robert R; Ptaszek, Marcin; Holten, Dewey; Bocian, David F
2016-01-28
Achieving tunable, intense near-infrared absorption in molecular architectures with properties suitable for solar light harvesting and biomedical studies is of fundamental interest. Herein, we report the photophysical, redox, and molecular-orbital characteristics of nine hydroporphyrin dyads and associated benchmark monomers that have been designed and synthesized to attain enhanced light harvesting. Each dyad contains two identical hydroporphyrins (chlorin or bacteriochlorin) connected by a linker (ethynyl or butadiynyl) at the macrocycle β-pyrrole (3- or 13-) or meso (15-) positions. The strong electronic communication between constituent chromophores is indicated by the doubling of prominent absorption features, split redox waves, and paired linear combinations of frontier molecular orbitals. Relative to the benchmarks, the chlorin dyads in toluene show substantial bathochromic shifts of the long-wavelength absorption band (17-31 nm), modestly reduced singlet excited-state lifetimes (τS = 3.6-6.2 ns vs 8.8-12.3 ns), and increased fluorescence quantum yields (Φf = 0.37-0.57 vs 0.34-0.39). The bacteriochlorin dyads in toluene show significant bathochromic shifts (25-57 nm) and modestly reduced τS (1.6-3.4 ns vs 3.5-5.3 ns) and Φf (0.09-0.19 vs 0.17-0.21) values. The τS and Φf values for the bacteriochlorin dyads are reduced substantially (up to ∼20-fold) in benzonitrile. The quenching is due primarily to the increased S1 → S0 internal conversion that is likely induced by increased contribution of charge-resonance configurations to the S1 excited state in the polar medium. The fundamental insights gained into the physicochemical properties of the strongly coupled hydroporphyrin dyads may aid their utilization in solar-energy conversion and photomedicine. PMID:26765839
Efficient parabolic evaluation of coupling terms in hybrid quantum/classical simulations
Bastida, Adolfo, E-mail: bastida@um.es [Departamento de Quimica Fisica, Facultad de Quimica, Universidad de Murcia, 30100 Murcia (Spain); Soler, Miguel Angel; Zuniga, Jose; Requena, Alberto [Departamento de Quimica Fisica, Facultad de Quimica, Universidad de Murcia, 30100 Murcia (Spain); Miguel, Beatriz [Departamento de Ingenieria Quimica y Ambiental, Universidad Politecnica de Cartagena, 30203 Cartagena (Spain)
2009-03-30
A parabolic interpolation function of time is proposed to evaluate the non-adiabatic coupling matrix elements and the adiabatic energies at intermediate times within the classical time integration interval in hybrid quantum/classical simulations. The accuracy and the computational efficiency of this parabolic approximation are illustrated by carrying out a numerical application to the well-studied vibrational relaxation of I{sub 2} in liquid xenon.
Coherent Preservation of Two-Qubit Quantum Entanglement in the Strong Coupling Region
The entanglement of two qubits is investigated in the range of their ultra-strongly coupling with a quantum oscillator. The two qubits are initially in four Bell states and they are under the control mechanism of the coherent state of the quantum oscillator. There are four parameters: the average number of the coherent state, the ultra-strong coupling strength, the ratio of two frequencies of qubit and oscillator, and the inter-interaction coupling of the two qubits in the mechanism, and they all are influential parameters on the entanglement of the two qubits. One Bell state |0〉 is easyily kept and is trivial case. The novel results show that there is one state | I0〉 among the other three Bell states which the entanglement of the two qubits could be almost completely preserved. The possibility is made into reality by the appropriate choice of the four influential parameters. We give two different schemes to choose the respective parameters to maintain the entanglment of | I0〉 almost undiminished. The results will be useful for the quantum information process. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Magnetic coupling in superconducting spin valves with strong ferromagnets
Flokstra, M.; van der Knaap, J. M.; Aarts, J.
2010-11-01
We investigate the magnetotransport behavior of ferromagnet (F)/superconductor/ferromagnet trilayers made of ferromagnetic Ni80Fe20 (Permalloy, Py) and superconducting Nb for temperatures both above and below the superconducting transition temperature Tc . In such devices, and for weak ferromagnets, Tc depends on the relative magnetization directions of the two F layers in such a way that TcP of the parallel (P) alignment is lower than TcAP of the antiparallel (AP) alignment (the so-called superconducting spin-valve effect). For strong magnets, the suppression of Andreev reflection may alter this picture, but also stray field effects become important, as is known from earlier work. We compare large-area samples with microstructured ones, and find blocklike switching in the latter. We show this not to be due to a switch between the P and AP states, but rather to dipolar coupling between domains which are forming in the two Py layers, making a stray-field scenario likely. We also present measurements of the depairing (critical) current Idp and show that a similar depression of superconductivity exists far below Tc as is found around Tc .
Weak-coupling superconductivity in a strongly correlated iron pnictide
Charnukha, A.; Post, K. W.; Thirupathaiah, S.; Pröpper, D.; Wurmehl, S.; Roslova, M.; Morozov, I.; Büchner, B.; Yaresko, A. N.; Boris, A. V.; Borisenko, S. V.; Basov, D. N.
2016-01-01
Iron-based superconductors have been found to exhibit an intimate interplay of orbital, spin, and lattice degrees of freedom, dramatically affecting their low-energy electronic properties, including superconductivity. Albeit the precise pairing mechanism remains unidentified, several candidate interactions have been suggested to mediate the superconducting pairing, both in the orbital and in the spin channel. Here, we employ optical spectroscopy (OS), angle-resolved photoemission spectroscopy (ARPES), ab initio band-structure, and Eliashberg calculations to show that nearly optimally doped NaFe0.978Co0.022As exhibits some of the strongest orbitally selective electronic correlations in the family of iron pnictides. Unexpectedly, we find that the mass enhancement of itinerant charge carriers in the strongly correlated band is dramatically reduced near the Γ point and attribute this effect to orbital mixing induced by pronounced spin-orbit coupling. Embracing the true band structure allows us to describe all low-energy electronic properties obtained in our experiments with remarkable consistency and demonstrate that superconductivity in this material is rather weak and mediated by spin fluctuations.
Large mass hierarchies from strongly-coupled dynamics
Athenodorou, Andreas; Bennett, Ed; Bergner, Georg; Elander, Daniel; Lin, C.-J. David; Lucini, Biagio; Piai, Maurizio
2016-06-01
Besides the Higgs particle discovered in 2012, with mass 125 GeV, recent LHC data show tentative signals for new resonances in diboson as well as diphoton searches at high center-of-mass energies (2 TeV and 750 GeV, respectively). If these signals are confirmed (or other new resonances are discovered at the TeV scale), the large hierarchies between masses of new bosons require a dynamical explanation. Motivated by these tentative signals of new physics, we investigate the theoretical possibility that large hierarchies in the masses of glueballs could arise dynamically in new strongly-coupled gauge theories extending the standard model of particle physics. We study lattice data on non-Abelian gauge theories in the (near-)conformal regime as well as a simple toy model in the context of gauge/gravity dualities. We focus our attention on the ratio R between the mass of the lightest spin-2 and spin-0 resonances, that for technical reasons is a particularly convenient and clean observable to study. For models in which (non-perturbative) large anomalous dimensions arise dynamically, we show indications that this mass ratio can be large, with R>5. Moreover,our results suggest that R might be related to universal properties of the IR fixed point. Our findings provide an interesting step towards understanding large mass ratios in the non-perturbative regime of quantum field theories with (near) IR conformal behaviour.
Large mass hierarchies from strongly-coupled dynamics
Athenodorou, Andreas; Bergner, Georg; Elander, Daniel; Lin, C -J David; Lucini, Biagio; Piai, Maurizio
2016-01-01
Besides the Higgs particle discovered in 2012, with mass 125 GeV, recent LHC data show tentative signals for new resonances in diboson as well as diphoton searches at high center-of-mass energies (2 TeV and 750 GeV, respectively). If these signals are confirmed (or other new resonances are discovered at the TeV scale), the large hierarchies between masses of new bosons require a dynamical explanation. Motivated by these tentative signals of new physics, we investigate the theoretical possibility that large hierarchies in the masses of glueballs could arise dynamically in new strongly-coupled gauge theories extending the standard model of particle physics. We study lattice data on non-Abelian gauge theories in the (near-)conformal regime as well as a simple toy model in the context of gauge/gravity dualities. We focus our attention on the ratio $R$ between the mass of the lightest spin-2 and spin-0 resonances, that for technical reasons is a particularly convenient and clean observable to study. For models in ...
Ionization equilibrium and equation of state in strongly coupled plasmas
Calculation of the physical properties of reacting plasmas depends on knowing the state of ionization and/or the state occupation numbers. Simple methods have often been used to estimate ionization balance in plasmas, but they are not adequate for understanding a variety of new experimental and observational measurements. Theoretical methods to determine the ionization state of partially ionized plasmas must confront the effects of density on bound states and strong ion coupling. These methods can be separated into two categories. Chemical picture methods consider the system to be composed of distinct chemical species. Consequently, it is necessary to assert the effect of the plasma environment on internal states of these species. On the other hand, physical picture methods view the plasma in terms of its fundamental constituents; i.e., electrons and nuclei, so that plasma effects on bound states are a basic component of the theory. A discussion of some work representative of both of these philosophies will be given. Some comparisons between theories and with recent helioseismic observations and shock experiments will also be given. (c) 2000 American Institute of Physics. (c)
Strong coupling between single atoms and non-transversal photons
Full text: We investigate the interaction between single quantum emitters and non-transversally polarized photons for which the electric field vector amplitude has a significant component in the direction of propagation. Even though this situation seems to be at odds with the description of light as a transverse wave, it regularly occurs when inter-facing or manipulating emitters with non-paraxial, guided, or evanescent light. Here, we quantitatively investigate this phenomenon for the case of single 85Rb atoms that strongly interact with a bottle-micro resonator - a novel type of whispering-gallery-mode (WGM) micro resonator. Our experimental results show that the non-transversal polarization decisively alters the physics of light–matter interaction. In addition they demonstrate that WGM resonators constitute a novel class of micro resonators that can, e.g., simultaneously sustain three orthogonally polarized eigenmodes. Building on our improved understanding, we investigate pathways to future WGM resonator based photonic devices. As a first example, we simultaneously interface the resonator with two coupling fibers, and use a single atom to route the incoming light between the optical fibers. (author)
Complex (dusty) plasmas—kinetic studies of strong coupling phenomenaa)
Morfill, Gregor E.; Ivlev, Alexei V.; Thomas, Hubertus M.
2012-05-01
"Dusty plasmas" can be found almost everywhere—in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere, and in the laboratory. In astrophysical plasmas, the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry, and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption, and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory, there is great interest in industrial processes (e.g., etching, vapor deposition) and—at the fundamental level—in the physics of strong coupling phenomena. Here, the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and space, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many-particle systems, including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10-12to10-9g), precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.
Complex (dusty) plasmas—kinetic studies of strong coupling phenomena
“Dusty plasmas” can be found almost everywhere—in the interstellar medium, in star and planet formation, in the solar system in the Earth’s atmosphere, and in the laboratory. In astrophysical plasmas, the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry, and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption, and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory, there is great interest in industrial processes (e.g., etching, vapor deposition) and—at the fundamental level—in the physics of strong coupling phenomena. Here, the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and space, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many-particle systems, including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10-12to10-9g), precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.
Dusty Plasmas - Kinetic Studies of Strong Coupling Phenomena
Morfill, Gregor
2011-10-01
``Dusty plasmas'' can be found almost everywhere - in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere and in the laboratory. In astrophysical plasmas the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory there is great interest in industrial processes (e.g. etching, vapor deposition) and at the fundamental physics level - the main topic here - the study of strong coupling phenomena. Here the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and pace, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many particle systems including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10-12 to 10-9 g) precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.
Complex (dusty) plasmas-kinetic studies of strong coupling phenomena
Morfill, Gregor E.; Ivlev, Alexei V.; Thomas, Hubertus M. [Max-Planck-Institut fuer Extraterrestrische Physik, D-85740 Garching (Germany)
2012-05-15
'Dusty plasmas' can be found almost everywhere-in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere, and in the laboratory. In astrophysical plasmas, the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry, and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption, and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory, there is great interest in industrial processes (e.g., etching, vapor deposition) and-at the fundamental level-in the physics of strong coupling phenomena. Here, the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and space, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many-particle systems, including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10{sup -12}to10{sup -9}g), precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.
Quantum-Classical Nonadiabatic Dynamics: Coupled- vs Independent-Trajectory Methods.
Agostini, Federica; Min, Seung Kyu; Abedi, Ali; Gross, E K U
2016-05-10
Trajectory-based mixed quantum-classical approaches to coupled electron-nuclear dynamics suffer from well-studied problems such as the lack of (or incorrect account for) decoherence in the trajectory surface hopping method and the inability of reproducing the spatial splitting of a nuclear wave packet in Ehrenfest-like dynamics. In the context of electronic nonadiabatic processes, these problems can result in wrong predictions for quantum populations and in unphysical outcomes for the nuclear dynamics. In this paper, we propose a solution to these issues by approximating the coupled electronic and nuclear equations within the framework of the exact factorization of the electron-nuclear wave function. We present a simple quantum-classical scheme based on coupled classical trajectories and test it against the full quantum mechanical solution from wave packet dynamics for some model situations which represent particularly challenging problems for the above-mentioned traditional methods. PMID:27030209
To move beyond dedicated links and networks, quantum communications signals must be integrated into networks carrying classical optical channels at power levels many orders of magnitude higher than the quantum signals themselves. We demonstrate the transmission of a 1550 nm quantum channel with up to two simultaneous 200 GHz spaced classical telecom channels, using reconfigurable optical add drop multiplexer (ROADM) technology for multiplexing and routing quantum and classical signals. The quantum channel is used to perform quantum key distribution (QKD) in the presence of noise generated as a by-product of the co-propagation of classical channels. We demonstrate that the dominant noise mechanism can arise from either four-wave mixing or spontaneous Raman scattering, depending on the optical path characteristics as well as the classical channel parameters. We quantify these impairments and discuss mitigation strategies.
Rosenberg, Danna [Los Alamos National Laboratory; Peterson, Charles G [Los Alamos National Laboratory; Dallmann, Nicholas [Los Alamos National Laboratory; Hughes, Richard J [Los Alamos National Laboratory; Mccabe, Kevin P [Los Alamos National Laboratory; Nordholt, Jane E [Los Alamos National Laboratory; Tyagi, Hush T [Los Alamos National Laboratory; Peters, Nicholas A [TELCORDIA TECHNOLOGIES; Toliver, Paul [TELCORDIA TECHNOLOGIES; Chapman, Thomas E [TELCORDIA TECHNOLOGIES; Runser, Robert J [TELCORDIA TECHNOLOGIES; Mcnown, Scott R [TELCORDIA TECHNOLOGIES
2008-01-01
To move beyond dedicated links and networks, quantum communications signals must be integrated into networks carrying classical optical channels at power levels many orders of magnitude higher than the quantum signals themselves. We demonstrate transmission of a 1550-nm quantum channel with up to two simultaneous 200-GHz spaced classical telecom channels, using ROADM (reconfigurable optical <1dd drop multiplexer) technology for multiplexing and routing quantum and classical signals. The quantum channel is used to perform quantum key distribution (QKD) in the presence of noise generated as a by-product of the co-propagation of classical channels. We demonstrate that the dominant noise mechanism can arise from either four-wave mixing or spontaneous Raman scattering, depending on the optical path characteristics as well <1S the classical channel parameters. We quantity these impairments and discuss mitigation strategies.
A novel framework of classical and quantum prisoner’s dilemma games on coupled networks
Deng, Xinyang; Zhang, Qi; Deng, Yong; Wang, Zhen
2016-03-01
Evolutionary games on multilayer networks are attracting growing interest. While among previous studies, the role of quantum games in such a infrastructure is still virgin and may become a fascinating issue across a myriad of research realms. To mimick two kinds of different interactive environments and mechanisms, in this paper a new framework of classical and quantum prisoner’s dilemma games on two-layer coupled networks is considered. Within the proposed model, the impact of coupling factor of networks and entanglement degree in quantum games on the evolutionary process has been studied. Simulation results show that the entanglement has no impact on the evolution of the classical prisoner’s dilemma, while the rise of the coupling factor obviously impedes cooperation in this game, and the evolution of quantum prisoner’s dilemma is greatly impacted by the combined effect of entanglement and coupling.
A novel framework of classical and quantum prisoner’s dilemma games on coupled networks
Deng, Xinyang; Zhang, Qi; Deng, Yong; Wang, Zhen
2016-01-01
Evolutionary games on multilayer networks are attracting growing interest. While among previous studies, the role of quantum games in such a infrastructure is still virgin and may become a fascinating issue across a myriad of research realms. To mimick two kinds of different interactive environments and mechanisms, in this paper a new framework of classical and quantum prisoner’s dilemma games on two-layer coupled networks is considered. Within the proposed model, the impact of coupling factor of networks and entanglement degree in quantum games on the evolutionary process has been studied. Simulation results show that the entanglement has no impact on the evolution of the classical prisoner’s dilemma, while the rise of the coupling factor obviously impedes cooperation in this game, and the evolution of quantum prisoner’s dilemma is greatly impacted by the combined effect of entanglement and coupling. PMID:26975447
A novel framework of classical and quantum prisoner's dilemma games on coupled networks.
Deng, Xinyang; Zhang, Qi; Deng, Yong; Wang, Zhen
2016-01-01
Evolutionary games on multilayer networks are attracting growing interest. While among previous studies, the role of quantum games in such a infrastructure is still virgin and may become a fascinating issue across a myriad of research realms. To mimick two kinds of different interactive environments and mechanisms, in this paper a new framework of classical and quantum prisoner's dilemma games on two-layer coupled networks is considered. Within the proposed model, the impact of coupling factor of networks and entanglement degree in quantum games on the evolutionary process has been studied. Simulation results show that the entanglement has no impact on the evolution of the classical prisoner's dilemma, while the rise of the coupling factor obviously impedes cooperation in this game, and the evolution of quantum prisoner's dilemma is greatly impacted by the combined effect of entanglement and coupling. PMID:26975447
Xiao, Cong; Li, Dingping
2016-06-15
Semiclassical magnetoelectric and magnetothermoelectric transport in strongly spin-orbit coupled Rashba two-dimensional electron systems is investigated. In the presence of a perpendicular classically weak magnetic field and short-range impurity scattering, we solve the linearized Boltzmann equation self-consistently. Using the solution, it is found that when Fermi energy E F locates below the band crossing point (BCP), the Hall coefficient is a nonmonotonic function of electron density n e and not inversely proportional to n e. While the magnetoresistance (MR) and Nernst coefficient vanish when E F locates above the BCP, non-zero MR and enhanced Nernst coefficient emerge when E F decreases below the BCP. Both of them are nonmonotonic functions of E F below the BCP. The different semiclassical magnetotransport behaviors between the two sides of the BCP can be helpful to experimental identifications of the band valley regime and topological change of Fermi surface in considered systems. PMID:27157714
Coupled-Trajectory Quantum-Classical Approach to Electronic Decoherence in Nonadiabatic Processes
Min, Seung Kyu; Agostini, Federica; Gross, E. K. U.
2015-08-01
We present a novel quantum-classical approach to nonadiabatic dynamics, deduced from the coupled electronic and nuclear equations in the framework of the exact factorization of the electron-nuclear wave function. The method is based on the quasiclassical interpretation of the nuclear wave function, whose phase is related to the classical momentum and whose density is represented in terms of classical trajectories. In this approximation, electronic decoherence is naturally induced as an effect of the coupling to the nuclei and correctly reproduces the expected quantum behavior. Moreover, the splitting of the nuclear wave packet is captured as a consequence of the correct approximation of the time-dependent potential of the theory. This new approach offers a clear improvement over Ehrenfest-like dynamics. The theoretical derivation presented in this Letter is supported by numerical results that are compared to quantum mechanical calculations.
Classical and thermodynamical aspects of black holes with conformally coupled scalar field hair
Winstanley, Elizabeth(Consortium for Fundamental Physics, School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH, United Kingdom)
2004-01-01
We discuss the existence, stability and classical thermodynamics of four-dimensional, spherically symmetric black hole solutions of the Einstein equations with a conformally coupled scalar field. We review the solutions existing in the literature with zero, positive and negative cosmological constant. We also outline new results on the thermodynamics of these black holes when the cosmological constant is non-zero.
From strong to ultrastrong coupling in circuit QED
In circuit quantum electrodynamics, the light-matter coupling strength can be tuned over several orders of magnitude and can even be increased to a significant fraction of the system energy. For a flux qubit coupled to a transmission line resonator, we have reached the regime of ultrastrong light-matter interaction and show experimental evidence for the breakdown of the Jaynes-Cummings-model. We present spectroscopic measurements for different coupling schemes of flux qubits and transmission line resonators and discuss the possibility to further increase the coupling strength and reach the regime of deep-ultrastrong coupling. For a complete characterization of our qubits we also perform time-domain spectroscopy measurements in order to determine the coherence times of our qubits.
D-brane physics. From weak to strong coupling
Vieira Lopes, Daniel Ordine
2013-01-10
In this thesis we discuss two aspects of branes relevant to high-energy phenomenology. First, we consider a single D6-brane wrapping a special Lagrangian cycle and the background space compactified in a Calabi-Yau orientifold the conditions needed to obtain a four-dimensional N=1 supersymmetric theory. We calculate the bosonic part of the effective action by performing a Kaluza-Klein reduction of the brane seven-dimensional action, and obtain the N=1 characteristic data. To discuss the moduli, we first fix the moduli from deformations of the background Calabi-Yau and study the D-brane deformation moduli space. We next allow for Calabi-Yau deformations, and show that the moduli space for complex structure deformations is corrected by the fields living on the D6-brane. We also calculate the scalar potential from D- and F-terms generated from brane and background configurations that would break the supersymmetry condition. We then, via Mirror Symmetry, relate the spectrum obtained in our work to the spectrum in Type IIB effective theory with D3- D5- and D7-branes, and we propose a Kaehler potential for the moduli space of brane deformations in Type IIB theories. In the second part of the thesis we discuss effects of brane intersections when the string coupling can become strong, and we work in the framework of F-theory. After reviewing the basics of F-theory constructions and a particular SU(5) model already discussed in the literature, we construct a model which contains a point of E{sub 8} singularity, and curves of E{sub 6} singularity. By explicitly resolving the space, we show that the resolution requires the introduction of higher dimensional fibers, and argue how we can circumvent this problem for the E{sub 6} curve, leading to the expected resolution that generate an E{sub 6} group, while at the E{sub 8} point we cannot make the resolution lead to an expected E{sub 8} structure.
SHAO Xiao-Qiang; ZHANG Shou
2008-01-01
We propose a scheme for one-step generation of cluster states with atoms sent through a thermal cavity with strong classical driving field, based on the resonant atom-cavity interaction so that the operating time is sharply short, which is important in the view of decoherence.
Gelin, Maxim F
2014-12-01
We consider a classical point particle bilinearly coupled to a harmonic bath. Assuming that the evolution of the particle is monitored on a timescale which is longer than the characteristic bath correlation time, we derive the Markovian master equation for the probability density of the particle. The relaxation operator of this master equation is evaluated analytically, without invoking the perturbation theory and the approximation of weak system-bath coupling. When the bath correlation time tends to zero, the Fokker-Planck equation is recovered. For a finite bath correlation time, the relaxation operator contains contributions of all orders in the system-bath coupling. PMID:25481131
Superconducting Split Ring Resonators for Ultra strong Coupling
Full text: We coupled superconducting Split Ring Resonators (SRR) to the cyclotron transition in two dimensional electron gases. Metallic SRRs have been proven to be a versatile structure to engineer Ultrastrong coupling between THz radiation and electronic transitions. Using Nb for the superconducting SRR structures enables an in-situ degree of tuning by means of temperature, magnetic field and optical irradiation. The latter of these techniques allows modifying the SRR properties on the picosecond time scale. (author)
From strong to weak coupling in holographic models of thermalization
Grozdanov, Sašo; Starinets, Andrei O
2016-01-01
We investigate the analytic structure of thermal energy-momentum tensor correlators at large but finite coupling in quantum field theories with gravity duals. We compute corrections to the quasinormal spectra of black branes due to the presence of higher derivative $R^2$ and $R^4$ terms in the action, focusing on the dual to $\\mathcal{N}=4$ SYM theory and Gauss-Bonnet gravity. We observe the appearance of new poles in the complex frequency plane at finite coupling. The new poles interfere with hydrodynamic poles of the correlators leading to the breakdown of hydrodynamic description at a coupling-dependent critical value of the wave-vector. The dependence of the critical wave vector on the coupling implies that the range of validity of the hydrodynamic description increases monotonically with the coupling. The behavior of the quasinormal spectrum at large but finite coupling may be contrasted with the known properties of the hierarchy of relaxation times determined by the spectrum of a linearized kinetic oper...
Shi, L; Rekola, H T; Martikainen, J -P; Moerland, R J; Törmä, P
2014-01-01
We study spatial coherence properties of a system composed of periodic silver nanoparticle arrays covered with a fluorescent organic molecule (DiD) film. The evolution of spatial coherence of this composite structure from the weak to the strong coupling regime is investigated by systematically varying the coupling strength between the localized DiD excitons and the collective, delocalized modes of the nanoparticle array known as surface lattice resonances. A gradual evolution of coherence from the weak to the strong coupling regime is observed, with the strong coupling features clearly visible in interference fringes. A high degree of spatial coherence is demonstrated in the strong coupling regime, even when the mode is very excitonlike (80%), in contrast to the purely localized nature of molecular excitons. We show that coherence appears in proportion to the weight of the plasmonic component of the mode throughout the weak-to-strong coupling crossover, providing evidence for the hybrid nature of the normal m...
Quark Gluon Plasma as a Strongly Coupled Color-Coulombic Plasma
Bannur, Vishnu Mayya
1998-01-01
We show that the extensively studied equation of state (EOS) of strongly coupled QED plasma fits the recent lattice EOS data of gluon plasma remarkably well, with appropriate modifications to take account of color degrees of freedom and running coupling constant. Hence we conclude that the quark gluon plasma near the critical temperature is a strongly coupled color-Coulombic plasma.
Investigation of gauge-fixed pure U(1) theory at strong coupling
Basak, S; De, Asit K.
2002-01-01
We numerically investigate the phase diagram of pure U(1) gauge theory with gauge fixing at strong gauge coupling. The FM-FMD phase transition, which proved useful in defining Abelian lattice chiral gauge theory, persists also at strong gauge coupling. However, there the transition seems no to be longer continuous. At large gauge couplings we find evidences for confinement.
Investigation of gauge-fixed pure U(1) theory at strong coupling
We numerically investigate the phase diagram of pure U(1) gauge theory with gauge fixing at strong gauge coupling. The FM-FMD phase transition, which proved useful in defining Abelian lattice chiral gauge theory, persists also at strong gauge coupling. However, there the transition seems no longer to be continuous. At large gauge couplings we find evidences for confinement