Photon statistics, antibunching and squeezed states

International Nuclear Information System (INIS)

Leuchs, G.

1986-01-01

This paper attempts to describe the status and addresses future prospects of experiments regarding photon antibunching, and squeezed states. Light correlation is presented in the framework of classical electrodynamics. The extension to quantized radiation fields is discussed and an introduction to the basic principles related to photon statistics, antibunching and squeezed states are presented. The effect of linear attenuation (beam splitters, neutral density filters, and detector quantum efficiency) on the detected signal is discussed. Experiments on the change of photon statistics by the nonlinear interaction of radiation fields with matter are described and some experimental observations of antibunching and sub-Poissonian photon statistics in resonance fluorescence and with possible schemes for the generation and detection of squeezed states are examined

Generation of coherent states of photon-added type via pathway of eigenfunctions

International Nuclear Information System (INIS)

Gorska, K; Penson, K A; Duchamp, G H E

2010-01-01

We obtain and investigate the regular eigenfunctions of simple differential operators x r d r+1 /dx r+1 , r = 1, 2, ..., with the eigenvalues equal to 1. With the help of these eigenfunctions, we construct a non-unitary analogue of a boson displacement operator which will be acting on the vacuum. In this way, we generate collective quantum states of the Fock space which are normalized and equipped with the resolution of unity with the positive weight functions that we obtain explicitly. These states are thus coherent states in the sense of Klauder. They span the truncated Fock space without first r lowest-lying basis states: |0), |1), ..., |r - 1). These states are squeezed, sub-Poissonian in nature and reminiscent of photon-added states in Agarwal and Tara (1991 Phys. Rev. A 43 492).

CMOS-compatible photonic devices for single-photon generation

Directory of Open Access Journals (Sweden)

Xiong Chunle

2016-09-01

Full Text Available Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal–oxide–semiconductor (CMOS-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

Single-photon generation with InAs quantum dots

International Nuclear Information System (INIS)

Santori, Charles; Fattal, David; Vuckovic, Jelena; Solomon, Glenn S; Yamamoto, Yoshihisa

2004-01-01

Single-photon generation using InAs quantum dots in pillar microcavities is described. The effects on performance of the excitation wavelength and polarization, and the collection bandwidth and polarization, are studied in detail. The efficiency and photon state purity of these devices have been measured, and issues affecting these parameters are discussed. Prospects for improved devices are also discussed

Generating photon pairs from a silicon microring resonator using an electronic step recovery diode for pump pulse generation

Energy Technology Data Exchange (ETDEWEB)

Savanier, Marc, E-mail: msavanier@eng.ucsd.edu; Mookherjea, Shayan, E-mail: smookherjea@eng.ucsd.edu [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093 (United States)

2016-06-20

Generation of photon pairs from compact, manufacturable, and inexpensive silicon (Si) photonic devices at room temperature may help develop practical applications of quantum photonics. An important characteristic of photon-pair generation is the two-photon joint spectral intensity, which describes the frequency correlations of the photon pair. Recent attempts to generate a factorizable photon-pair state suitable for heralding have used short optical pump pulses from mode-locked lasers, which are much more expensive and bigger table-top or rack-sized instruments compared with the Si microchip used for generating photon pairs, and thus dominate the cost and inhibit the miniaturization of the source. Here, we generate photon pairs from an Si microring resonator by using an electronic step-recovery diode to drive an electro-optic modulator which carves the pump light from a continuous-wave laser diode into pulses of the appropriate width, thus potentially eliminating the need for optical mode-locked lasers.

Photon virtual bound state

International Nuclear Information System (INIS)

Inoue, J.; Ohtaka, K.

2004-01-01

We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

Photon generator

Science.gov (United States)

Srinivasan-Rao, Triveni

2002-01-01

A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

Strongly correlated photons generated by coupling a three- or four-level system to a waveguide

Science.gov (United States)

Zheng, Huaixiu; Gauthier, Daniel J.; Baranger, Harold U.

2012-04-01

We study the generation of strongly correlated photons by coupling an atom to photonic quantum fields in a one-dimensional waveguide. Specifically, we consider a three-level or four-level system for the atom. Photon-photon bound states emerge as a manifestation of the strong photon-photon correlation mediated by the atom. Effective repulsive or attractive interaction between photons can be produced, causing either suppressed multiphoton transmission (photon blockade) or enhanced multiphoton transmission (photon-induced tunneling). As a result, nonclassical light sources can be generated on demand by sending coherent states into the proposed system. We calculate the second-order correlation function of the transmitted field and observe bunching and antibunching caused by the bound states. Furthermore, we demonstrate that the proposed system can produce photon pairs with a high degree of spectral entanglement, which have a large capacity for carrying information and are important for large-alphabet quantum communication.

Latest Advances in the Generation of Single Photons in Silicon Carbide

Directory of Open Access Journals (Sweden)

Albert Boretti

2016-06-01

Full Text Available The major barrier for optical quantum information technologies is the absence of reliable single photons sources providing non-classical light states on demand which can be easily and reliably integrated with standard processing protocols for quantum device fabrication. New methods of generation at room temperature of single photons are therefore needed. Heralded single photon sources are presently being sought based on different methods built on different materials. Silicon Carbide (SiC has the potentials to serve as the preferred material for quantum applications. Here, we review the latest advances in single photon generation at room temperatures based on SiC.

Spatiotemporal correlations in entangled photons generated by spontaneous parametric down conversion

International Nuclear Information System (INIS)

Osorio, Clara I; Valencia, Alejandra; Torres, Juan P

2008-01-01

In most configurations aimed at generating entangled photons based on spontaneous parametric down conversion (SPDC), the generated pairs of photons are required to be entangled in only one degree of freedom. Any distinguishing information coming from the other degrees of freedom that characterize the photon should be suppressed to avoid correlations with the degree of freedom of interest. However, this suppression is not always possible. Here, we show how the frequency information available affects the purity of the two-photon state in space, revealing a correlation between the frequency and the space degrees of freedom. This correlation should be taken into account to calculate the total amount of entanglement between the photons.

Experimental test of the strongly nonclassical character of a noisy squeezed single-photon state

DEFF Research Database (Denmark)

Jezek, M.; Tipsmark, A.; Dong, R.

2012-01-01

We experimentally verify the quantum non-Gaussian character of a conditionally generated noisy squeezed single-photon state with a positive Wigner function. Employing an optimized witness based on probabilities of squeezed vacuum and squeezed single-photon states, we prove that the state cannot...... be expressed as a mixture of Gaussian states. In our experiment, the non-Gaussian state is generated by conditional subtraction of a single photon from a squeezed vacuum state. The state is probed with a homodyne detector and the witness is determined by averaging a suitable pattern function over the measured...

Unambiguous modification of nonorthogonal single- and two-photon polarization states

International Nuclear Information System (INIS)

Torres-Ruiz, F. A.; Aguirre, J.; Delgado, A.; Lima, G.; Neves, L.; Roa, L.; Saavedra, C.; Padua, S.

2009-01-01

In this paper we propose a probabilistic method which allows an unambiguous modification of two nonorthogonal quantum states. We experimentally implement this protocol by using two-photon polarization states generated in the process of spontaneous parametric down conversion. In the experiment, for codifying initial quantum states, we consider single-photon states and heralded detection. We show that the application of this protocol to entangled states allows a fine control of the amount of entanglement of the initial state.

Effect of the coherent cancellation of the two-photon resonance on the generation of vacuum ultraviolet light by two-photon reasonantly enhanced four-wave mixing

International Nuclear Information System (INIS)

Payne, M.G.; Garrett, W.R.; Judish, J.P.; Wunderlich, R.

1988-11-01

Many of the most impressive demonstrations of the efficient generation of vacuum ultraviolet (VUV) light have made use of two- photon resonantly enhanced four-wave mixing to generate light at ω/sub VUV/ = 2ω/sub L1/ +- ω/sub L2/. The two-photon resonance state is coupled to the ground state both by two photons from the first laser, or by a photon from the second laser and one from the generated VUV beam. We show here that these two coherent pathways destructively interfere once the second laser is made sufficiently intense, thereby leading to an important limiting effect on the achievable conversion efficiency. 4 refs

Nonclassicality of Photon-Added Displaced Thermal State via Quantum Phase-Space Distributions

Science.gov (United States)

Zhang, Ran; Meng, Xiang-Guo; Du, Chuan-Xun; Wang, Ji-Suo

2018-02-01

We introduce a new kind of nonclassical mixed state generated by adding arbitrary photons to a displaced thermal state, i.e., the photon-added displaced thermal state (PADTS), and obtain the normalization factor, which is simply related to two-variable Hermite polynomials. We also discuss the nonclassicality of the PADTS by considering quantum phase-space distributions. The results indicate that the value of the photon count statistics is maximum when the number of detected photons is equal to the number of added photons, and that the photon-added operation has a similar modulation effect with increasing displacement. Moreover, the negative volume of the Wigner function for the PADTS takes a maximal value for a specific photon-added number.

Dynamical generation of maximally entangled states in two identical cavities

International Nuclear Information System (INIS)

Alexanian, Moorad

2011-01-01

The generation of entanglement between two identical coupled cavities, each containing a single three-level atom, is studied when the cavities exchange two coherent photons and are in the N=2,4 manifolds, where N represents the maximum number of photons possible in either cavity. The atom-photon state of each cavity is described by a qutrit for N=2 and a five-dimensional qudit for N=4. However, the conservation of the total value of N for the interacting two-cavity system limits the total number of states to only 4 states for N=2 and 8 states for N=4, rather than the usual 9 for two qutrits and 25 for two five-dimensional qudits. In the N=2 manifold, two-qutrit states dynamically generate four maximally entangled Bell states from initially unentangled states. In the N=4 manifold, two-qudit states dynamically generate maximally entangled states involving three or four states. The generation of these maximally entangled states occurs rather rapidly for large hopping strengths. The cavities function as a storage of periodically generated maximally entangled states.

Generation of Path-Encoded Greenberger-Horne-Zeilinger States

Science.gov (United States)

Bergamasco, N.; Menotti, M.; Sipe, J. E.; Liscidini, M.

2017-11-01

We study the generation of Greenberger-Horne-Zeilinger (GHZ) states of three path-encoded photons. Inspired by the seminal work of Bouwmeester et al. [Phys. Rev. Lett. 82, 1345 (1999), 10.1103/PhysRevLett.82.1345] on polarization-entangled GHZ states, we find a corresponding path representation for the photon states of an optical circuit, identify the elements required for the state generation, and propose a possible implementation of our strategy. Besides the practical advantage of employing an integrated system that can be fabricated with proven lithographic techniques, our example suggests that it is possible to enhance the generation efficiency by using microring resonators.

Resource-efficient generation of linear cluster states by linear optics with postselection

International Nuclear Information System (INIS)

Uskov, D B; Alsing, P M; Fanto, M L; Szep, A; Smith, A M; Kaplan, L; Kim, R

2015-01-01

We report on theoretical research in photonic cluster-state computing. Finding optimal schemes of generating non-classical photonic states is of critical importance for this field as physically implementable photon–photon entangling operations are currently limited to measurement-assisted stochastic transformations. A critical parameter for assessing the efficiency of such transformations is the success probability of a desired measurement outcome. At present there are several experimental groups that are capable of generating multi-photon cluster states carrying more than eight qubits. Separate photonic qubits or small clusters can be fused into a single cluster state by a probabilistic optical CZ gate conditioned on simultaneous detection of all photons with 1/9 success probability for each gate. This design mechanically follows the original theoretical scheme of cluster state generation proposed more than a decade ago by Raussendorf, Browne and Briegel. The optimality of the destructive CZ gate in application to linear optical cluster state generation has not been analyzed previously. Our results reveal that this method is far from the optimal one. Employing numerical optimization we have identified that the maximal success probability of fusing n unentangled dual-rail optical qubits into a linear cluster state is equal to (1/2) n−1 ; an m-tuple of photonic Bell pair states, commonly generated via spontaneous parametric down-conversion, can be fused into a single cluster with the maximal success probability of (1/4) m−1 . (paper)

Resonant Photonic States in Coupled Heterostructure Photonic Crystal Waveguides

Directory of Open Access Journals (Sweden)

Sabarinathan J

2010-01-01

Full Text Available Abstract In this paper, we study the photonic resonance states and transmission spectra of coupled waveguides made from heterostructure photonic crystals. We consider photonic crystal waveguides made from three photonic crystals A, B and C, where the waveguide heterostructure is denoted as B/A/C/A/B. Due to the band structure engineering, light is confined within crystal A, which thus act as waveguides. Here, photonic crystal C is taken as a nonlinear photonic crystal, which has a band gap that may be modified by applying a pump laser. We have found that the number of bound states within the waveguides depends on the width and well depth of photonic crystal A. It has also been found that when both waveguides are far away from each other, the energies of bound photons in each of the waveguides are degenerate. However, when they are brought close to each other, the degeneracy of the bound states is removed due to the coupling between them, which causes these states to split into pairs. We have also investigated the effect of the pump field on photonic crystal C. We have shown that by applying a pump field, the system may be switched between a double waveguide to a single waveguide, which effectively turns on or off the coupling between degenerate states. This reveals interesting results that can be applied to develop new types of nanophotonic devices such as nano-switches and nano-transistors.

General linear-optical quantum state generation scheme: Applications to maximally path-entangled states

International Nuclear Information System (INIS)

VanMeter, N. M.; Lougovski, P.; Dowling, Jonathan P.; Uskov, D. B.; Kieling, K.; Eisert, J.

2007-01-01

We introduce schemes for linear-optical quantum state generation. A quantum state generator is a device that prepares a desired quantum state using product inputs from photon sources, linear-optical networks, and postselection using photon counters. We show that this device can be concisely described in terms of polynomial equations and unitary constraints. We illustrate the power of this language by applying the Groebner-basis technique along with the notion of vacuum extensions to solve the problem of how to construct a quantum state generator analytically for any desired state, and use methods of convex optimization to identify bounds to success probabilities. In particular, we disprove a conjecture concerning the preparation of the maximally path-entangled |n,0>+|0,n> (NOON) state by providing a counterexample using these methods, and we derive a new upper bound on the resources required for NOON-state generation

Doppler-free two-photon spectroscopy of Yb atoms and efficient generation of a cascade of two photons at 611.3 nm and 555.8 nm

International Nuclear Information System (INIS)

Song, Minsoo; Yoon, Duseong; Yoon, Taihyun

2011-01-01

We performed high-resolution Doppler-free two-photon spectroscopy of Yb atoms in an effusive atomic beam and generated a cascade of two photons at 611.3 nm (idler) and 555.8 nm (signal) with a narrow bandwidth of 37 MHz. Efficient population transfer from the ground state (6s 2 1 S 0 ) to the upper state (6s7s 1 S 0 ), where direct transition at 291.1 nm is dipole forbidden, was achieved through a resonant two-photon excitation enhanced by the electromagnetically-induced transparency mediated by the intermediate state (6s6p 1 P 1 ). From the upper state, a cascade of two photons in sequence was emitted via the spin triplet state (6s 2 3 P 1 ). Numerical calculations of the density matrix equations taking into account the residual Doppler effect and strong driving fields explain quantitatively the experimental results for the dependences of the idler and the signal beam intensities on the various parameters of the driving fields. We report on the generation of a cascade of two photons with fluxes at the level of a few times 10 6 photons/s detected at a solid angle of 0.01 sr.

Doppler-free two-photon spectroscopy of Yb atoms and efficient generation of a cascade of two photons at 611.3 nm and 555.8 nm

Energy Technology Data Exchange (ETDEWEB)

Song, Minsoo; Yoon, Duseong; Yoon, Taihyun [Korea University, Seoul (Korea, Republic of)

2011-10-15

We performed high-resolution Doppler-free two-photon spectroscopy of Yb atoms in an effusive atomic beam and generated a cascade of two photons at 611.3 nm (idler) and 555.8 nm (signal) with a narrow bandwidth of 37 MHz. Efficient population transfer from the ground state (6s{sup 2} {sup 1}S{sub 0}) to the upper state (6s7s {sup 1}S{sub 0}), where direct transition at 291.1 nm is dipole forbidden, was achieved through a resonant two-photon excitation enhanced by the electromagnetically-induced transparency mediated by the intermediate state (6s6p {sup 1}P{sub 1}). From the upper state, a cascade of two photons in sequence was emitted via the spin triplet state (6s{sup 2} {sup 3}P{sub 1}). Numerical calculations of the density matrix equations taking into account the residual Doppler effect and strong driving fields explain quantitatively the experimental results for the dependences of the idler and the signal beam intensities on the various parameters of the driving fields. We report on the generation of a cascade of two photons with fluxes at the level of a few times 10{sup 6} photons/s detected at a solid angle of 0.01 sr.

Effects of multi-photon interferences from internally generated fields in strongly resonant systems

International Nuclear Information System (INIS)

Deng, Lu; Payne, Marvin G.; Garrett, William R.

2006-01-01

In studies of various nonlinear optical phenomena, strong resonant features in the atomic or molecular response to multi-photon driven processes have been used to greatly enhance the visibility of otherwise weak higher-order processes. However, there are well defined circumstances where a multi-photon-resonant response of a target system leads to the generation of one or more new electromagnetic fields that can drastically change the overall system response from what would be expected from the imposed laser fields alone. New effects can occur and dominate some aspects of the nonlinear optical response because of the constructive or destructive interference between transition amplitudes along multiple excitation pathways between a given set of optically coupled states, where one of the pathways involve internally generated field(s). Under destructive interference some resonant enhancements can become completely canceled (suppressed). This review focuses on the class of optical interference effects associated with internally generated fields, that have been found to be capable of influencing a very significant number of basic physical phenomena in gas or vapor phase systems. It provides a historical overview of experimental and theoretical developments and a modern understanding of the underlying physics and its various manifestations that include: suppression of multi-photon excitation processes, suppression of stimulated emissions (Raman, hyper-Raman, and optically pumped stimulated emissions), saturation of parametric wave-mixing, pressure and beam-geometry dependent shifting of multi-photon-resonant absorption lines, and the suppression of Autler-Townes splitting and ac-stark shifts. Additionally, optical interference effects in some modern contexts, such as achieving multi-photon induced transparency, establishing single-photon self-interference based induced transparency, and generating entangled single photon states, are reviewed

Split-step scheme for photon-pair generation through spontaneous four-wave mixing

DEFF Research Database (Denmark)

Koefoed, Jacob Gade; Christensen, Jesper Bjerge; Rottwitt, Karsten

2017-01-01

The rapid development of quantum information technology requires the ability to reliably create and distribute single photons [1]. Photon-pair production through spontaneous four-wave mixing (SpFWM) allows heralded single photons to be generated at communication wavelengths and in fiber, compatible...... with conventional communication systems, with small losses. Creating single photons in desired quantum states require careful design of waveguide structures. This is greatly facilitated by a general numerical approach as presented here. Additionally, such a numerical approach allows detailed analysis of real...... systems where all relevent effects are included....

Multi-dimensional photonic states from a quantum dot

Science.gov (United States)

Lee, J. P.; Bennett, A. J.; Stevenson, R. M.; Ellis, D. J. P.; Farrer, I.; Ritchie, D. A.; Shields, A. J.

2018-04-01

Quantum states superposed across multiple particles or degrees of freedom offer an advantage in the development of quantum technologies. Creating these states deterministically and with high efficiency is an ongoing challenge. A promising approach is the repeated excitation of multi-level quantum emitters, which have been shown to naturally generate light with quantum statistics. Here we describe how to create one class of higher dimensional quantum state, a so called W-state, which is superposed across multiple time bins. We do this by repeated Raman scattering of photons from a charged quantum dot in a pillar microcavity. We show this method can be scaled to larger dimensions with no reduction in coherence or single-photon character. We explain how to extend this work to enable the deterministic creation of arbitrary time-bin encoded qudits.

Hybrid Integration of Solid-State Quantum Emitters on a Silicon Photonic Chip.

Science.gov (United States)

Kim, Je-Hyung; Aghaeimeibodi, Shahriar; Richardson, Christopher J K; Leavitt, Richard P; Englund, Dirk; Waks, Edo

2017-12-13

Scalable quantum photonic systems require efficient single photon sources coupled to integrated photonic devices. Solid-state quantum emitters can generate single photons with high efficiency, while silicon photonic circuits can manipulate them in an integrated device structure. Combining these two material platforms could, therefore, significantly increase the complexity of integrated quantum photonic devices. Here, we demonstrate hybrid integration of solid-state quantum emitters to a silicon photonic device. We develop a pick-and-place technique that can position epitaxially grown InAs/InP quantum dots emitting at telecom wavelengths on a silicon photonic chip deterministically with nanoscale precision. We employ an adiabatic tapering approach to transfer the emission from the quantum dots to the waveguide with high efficiency. We also incorporate an on-chip silicon-photonic beamsplitter to perform a Hanbury-Brown and Twiss measurement. Our approach could enable integration of precharacterized III-V quantum photonic devices into large-scale photonic structures to enable complex devices composed of many emitters and photons.

Intrinsically narrowband pair photon generation in microstructured fibres

Energy Technology Data Exchange (ETDEWEB)

Clark, Alex; Bell, Bryn; Fulconis, Jeremie; Halder, Matthaeus M; Cemlyn, Ben; Rarity, John G [Centre for Communications Research, Department of Electrical and Electronic Engineering, University of Bristol, Merchant Venturers Building, Woodland Road, Bristol BS8 1UB (United Kingdom); Alibart, Olivier [Laboratoire de Physique de la Matiere Condensee, Unite Mixte de Recherche 6622, Centre National de la Recherche Scientifique, Universite de Nice-Sophia Antipolis, Parc Valrose 06108, Nice 2 (France); Xiong Chunle; Wadsworth, William J, E-mail: alex.clark@bristol.ac.uk [Centre for Photonics and Photonic Materials, Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

2011-06-15

In this paper, we study the tailoring of photon spectral properties generated by four-wave mixing in a birefringent photonic crystal fibre (PCF). The aim is to produce intrinsically narrow-band photons and hence to achieve high non-classical interference visibility and generate high-fidelity entanglement without any requirement for spectral filtering, leading to high effective detection efficiencies. We show unfiltered Hong-Ou-Mandel interference visibilities of 77% between photons from the same PCF and 80% between separate sources. We compare results from modelling the PCF to these experiments and analyse photon purities.

Unidirectional edge states in topological honeycomb-lattice membrane photonic crystals.

Science.gov (United States)

Anderson, P Duke; Subramania, Ganapathi

2017-09-18

Photonic analogs of electronic systems with topologically non-trivial behavior such as unidirectional scatter-free propagation has tremendous potential for transforming photonic systems. Like in electronics topological behavior can be observed in photonics for systems either preserving time-reversal (TR) symmetry or explicitly breaking it. TR symmetry breaking requires magneto-optic photonics crystals (PC) or generation of synthetic gauge fields. For on-chip photonics that operate at optical frequencies both are quite challenging because of poor magneto-optic response of materials or substantial nanofabrication challenges in generating synthetic gauge fields. A recent work by Ma, et al. [Phys. Rev. Lett.114, 223901 (2015)] based on preserving pseudo TR symmetry offers a promising design scheme for observing unidirectional edge states in a modified honeycomb photonic crystal (PC) lattice of circular rods that offers encouraging alternatives. Here we propose through bandstructure calculations the inverse system of modified honeycomb PC of circular holes in a dielectric membrane which is more attractive from fabrication standpoint for on-chip applications. We observe trivial and non-trivial bandgaps as well as unidirectional edge states of opposite helicity propagating in opposite directions at the interface of a trivial and non-trivial PC structures. Around 1550nm operating wavelength ~55nm of bandwidth is possible for practicable values of design parameters (lattice constant, hole radii, membrane thickness, scaling factor etc.) and robust to reasonable variations in those parameters.

Simulation of multi-photon emission isotopes using time-resolved SimSET multiple photon history generator

Energy Technology Data Exchange (ETDEWEB)

Chiang, Chih-Chieh; Lin, Hsin-Hon; Lin, Chang-Shiun; Chuang, Keh-Shih [Department of Biomedical Engineering and Environmental Sciences, National Tsing-HuaUniversity, Hsinchu, Taiwan (China); Jan, Meei-Ling [Health Physics Division, Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan, Taiwan (China)

2015-07-01

Abstract-Multiple-photon emitters, such as In-111 or Se-75, have enormous potential in the field of nuclear medicine imaging. For example, Se-75 can be used to investigate the bile acid malabsorption and measure the bile acid pool loss. The simulation system for emission tomography (SimSET) is a well-known Monte Carlo simulation (MCS) code in nuclear medicine for its high computational efficiency. However, current SimSET cannot simulate these isotopes due to the lack of modeling of complex decay scheme and the time-dependent decay process. To extend the versatility of SimSET for simulation of those multi-photon emission isotopes, a time-resolved multiple photon history generator based on SimSET codes is developed in present study. For developing the time-resolved SimSET (trSimSET) with radionuclide decay process, the new MCS model introduce new features, including decay time information and photon time-of-flight information, into this new code. The half-life of energy states were tabulated from the Evaluated Nuclear Structure Data File (ENSDF) database. The MCS results indicate that the overall percent difference is less than 8.5% for all simulation trials as compared to GATE. To sum up, we demonstrated that time-resolved SimSET multiple photon history generator can have comparable accuracy with GATE and keeping better computational efficiency. The new MCS code is very useful to study the multi-photon imaging of novel isotopes that needs the simulation of lifetime and the time-of-fight measurements. (authors)

On-demand generation of background-free single photons from a solid-state source

Science.gov (United States)

Schweickert, Lucas; Jöns, Klaus D.; Zeuner, Katharina D.; Covre da Silva, Saimon Filipe; Huang, Huiying; Lettner, Thomas; Reindl, Marcus; Zichi, Julien; Trotta, Rinaldo; Rastelli, Armando; Zwiller, Val

2018-02-01

True on-demand high-repetition-rate single-photon sources are highly sought after for quantum information processing applications. However, any coherently driven two-level quantum system suffers from a finite re-excitation probability under pulsed excitation, causing undesirable multi-photon emission. Here, we present a solid-state source of on-demand single photons yielding a raw second-order coherence of g(2 )(0 )=(7.5 ±1.6 )×10-5 without any background subtraction or data processing. To this date, this is the lowest value of g(2 )(0 ) reported for any single-photon source even compared to the previously reported best background subtracted values. We achieve this result on GaAs/AlGaAs quantum dots embedded in a low-Q planar cavity by employing (i) a two-photon excitation process and (ii) a filtering and detection setup featuring two superconducting single-photon detectors with ultralow dark-count rates of (0.0056 ±0.0007 ) s-1 and (0.017 ±0.001 ) s-1, respectively. Re-excitation processes are dramatically suppressed by (i), while (ii) removes false coincidences resulting in a negligibly low noise floor.

A Next Generation BioPhotonics Workstation

DEFF Research Database (Denmark)

Glückstad, Jesper; Palima, Darwin; Tauro, Sandeep

2011-01-01

We are developing a Next Generation BioPhotonics Workstation to be applied in research on regulated microbial cell growth including their underlying physiological mechanisms, in vivo characterization of cell constituents and manufacturing of nanostructures and meta-materials.......We are developing a Next Generation BioPhotonics Workstation to be applied in research on regulated microbial cell growth including their underlying physiological mechanisms, in vivo characterization of cell constituents and manufacturing of nanostructures and meta-materials....

Vibrational excitation of hydrogen molecules by two-photon absorption and third-harmonic generation

Science.gov (United States)

Miyamoto, Yuki; Hara, Hideaki; Hiraki, Takahiro; Masuda, Takahiko; Sasao, Noboru; Uetake, Satoshi; Yoshimi, Akihiro; Yoshimura, Koji; Yoshimura, Motohiko

2018-01-01

We report the coherent excitation of the vibrational state of hydrogen molecules by two-photon absorption and the resultant third-harmonic generation (THG). Parahydrogen molecules cooled by liquid nitrogen are irradiated by mid-infrared nanosecond pulses at 4.8 μm with a nearly Fourier-transform-limited linewidth. The first excited vibrational state of parahydrogen is populated by two-photon absorption of the mid-infrared photons. Because of the narrow linewidth of the mid-infrared pulses, coherence between the ground and excited states is sufficient to induce higher-order processes. Near-infrared photons from the THG are observed at 1.6 μm. The dependence of the intensity of the near-infrared radiation on mid-infrared pulse energy, target pressure, and cell length is determined. We used a simple formula for THG with consideration of realistic experimental conditions to explain the observed results.

Selective two-photon excitation of a vibronic state by correlated photons.

Science.gov (United States)

Oka, Hisaki

2011-03-28

We theoretically investigate the two-photon excitation of a molecular vibronic state by correlated photons with energy anticorrelation. A Morse oscillator having three sets of vibronic states is used, as an example, to evaluate the selectivity and efficiency of two-photon excitation. We show that a vibrational mode can be selectively excited with high efficiency by the correlated photons, without phase manipulation or pulse-shaping techniques. This can be achieved by controlling the quantum correlation so that the photon pair concurrently has two pulse widths, namely, a temporally narrow width and a spectrally narrow width. Though this concurrence is seemingly contradictory, we can create such a photon pair by tailoring the quantum correlation between two photons.

Generation of picosecond pulsed coherent state superpositions

DEFF Research Database (Denmark)

Dong, Ruifang; Tipsmark, Anders; Laghaout, Amine

2014-01-01

We present the generation of approximated coherent state superpositions-referred to as Schrodinger cat states-by the process of subtracting single photons from picosecond pulsed squeezed states of light. The squeezed vacuum states are produced by spontaneous parametric down-conversion (SPDC...... which exhibit non-Gaussian behavior. (C) 2014 Optical Society of America...

Possibility of producing the event-ready two-photon polarization entangled state with normal photon detectors

International Nuclear Information System (INIS)

Wang Xiangbin

2003-01-01

We propose a scheme to produce the maximally two-photon polarization entangled state with single-photon sources and the passive linear optics devices. In particular, our scheme only requires the normal photon detectors which distinguish the vacuum and non-vacuum Fock number states. A sophisticated photon detector distinguishing between one-photon state and two-photon state is unnecessary in the scheme

Quantum properties of counterpropagating two-photon states generated in a planar waveguide

Czech Academy of Sciences Publication Activity Database

Peřina ml., Jan

2008-01-01

Roč. 77, č. 1 (2008), 013803/1-013803/14 ISSN 1050-2947 R&D Projects: GA MŠk(CZ) 1M06002 Institutional research plan: CEZ:AV0Z10100522 Keywords : quantum properties * two-photon states Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.908, year: 2008

Generation of entangled coherent states for distant Bose-Einstein condensates via electromagnetically induced transparency

International Nuclear Information System (INIS)

Kuang, L.-M.; Chen Zengbing; Pan Jianwei

2007-01-01

We propose a method to generate entangled coherent states between two spatially separated atomic Bose-Einstein condensates (BECs) via the technique of electromagnetically induced transparency (EIT). Two strong coupling laser beams and two entangled probe laser beams are used to cause two distant BECs to be in EIT states and to generate an atom-photon entangled state between probe lasers and distant BECs. The two BECs are initially in unentangled product coherent states while the probe lasers are initially in an entangled state. Entangled states of two distant BECs can be created through the performance of projective measurements upon the two outgoing probe lasers under certain conditions. Concretely, we propose two protocols to show how to generate entangled coherent states of the two distant BECs. One is a single-photon scheme in which an entangled single-photon state is used as the quantum channel to generate entangled distant BECs. The other is a multiphoton scheme where an entangled coherent state of the probe lasers is used as the quantum channel. Additionally, we also obtain some atom-photon entangled states of particular interest such as entangled states between a pair of optical Bell states (or quasi-Bell-states) and a pair of atomic entangled coherent states (or quasi-Bell-states)

A light-matter quantum interface : ion-photon entanglement and state mapping

International Nuclear Information System (INIS)

Stute, A.

2012-01-01

Quantum mechanics promises to have a great impact on computation. Motivated by the long-term vision of a universal quantum computer that speeds up certain calculations, the field of quantum information processing has been growing steadily over the last decades. Although a variety of quantum systems consisting of a few qubits have been used to implement initial algorithms successfully, decoherence makes it difficult to scale up these systems. A powerful technique, however, could surpass any size limitation: the connection of individual quantum processors in a network. In a quantum network, ''flying'' qubits coherently transfer information between the stationary nodes of the network that store and process quantum information. Ideal candidates for the physical implementation of nodes are single atoms that exhibit long storage times; optical photons, which travel at the speed of light, are ideal information carriers. For coherent information transfer between atom and photon, a quantum interface has to couple the atom to a particular optical mode. This thesis reports on the implementation of a quantum interface by coupling a single trapped 40 Ca+ ion to the mode of a high-finesse optical resonator. Single intra-cavity photons are generated in a vacuum-stimulated Raman process between two atomic states driven by a laser and the cavity vacuum field. In this Raman process, all Zeeman substates of the atom are spectroscopically resolved by tuning the frequency of the laser; via addressing specific atomic states, the polarization of the generated cavity photon is controlled, defining the photonic qubit. The electronic state of the ion is initialized, coherently manipulated, and read out via driving the quadrupole transition. With these techniques in hand, we have demonstrated two protocols for quantum communication. The first protocol, ion-photon entanglement, is regarded as a key resource of distributed quantum information processing. In our realization, we control both

Two-photon spin generation and detection

International Nuclear Information System (INIS)

Miah, M Idrish

2009-01-01

A time- and polarization-resolved two-photon pump-probe investigation is performed in lightly doped GaAs. We generate spin-polarized electrons in bulk GaAs at various temperatures using right-circularly polarized two-photon excitation and detect them by probing the spin-dependent transmission of the sample. The spin polarization (P) of conduction band electrons, as measured using probe pulses with the same (right) and opposite (left) circular polarization, is measured in dependences of pump-probe delay (Δt), lattice temperature (T L ), doping density (n) as well as of the excess photon energy ΔE 2ω = ℎ2ω - E g , where E g is the band gap energy. P is found to be decayed with Δt and enhanced with the decrease in T L or the increase in n. It is also found that P decreases with the increase in ΔE 2ω and depolarizes rapidly for ΔE 2ω > ΔE SO , where ΔE SO is the spin-orbit splitting energy. The results demonstrate that due to a much longer absorption depth highly polarized spins can be generated optically by two-photon pumping of bulk semiconductors.

Physical-depth architectural requirements for generating universal photonic cluster states

Science.gov (United States)

Morley-Short, Sam; Bartolucci, Sara; Gimeno-Segovia, Mercedes; Shadbolt, Pete; Cable, Hugo; Rudolph, Terry

2018-01-01

Most leading proposals for linear-optical quantum computing (LOQC) use cluster states, which act as a universal resource for measurement-based (one-way) quantum computation. In ballistic approaches to LOQC, cluster states are generated passively from small entangled resource states using so-called fusion operations. Results from percolation theory have previously been used to argue that universal cluster states can be generated in the ballistic approach using schemes which exceed the critical threshold for percolation, but these results consider cluster states with unbounded size. Here we consider how successful percolation can be maintained using a physical architecture with fixed physical depth, assuming that the cluster state is continuously generated and measured, and therefore that only a finite portion of it is visible at any one point in time. We show that universal LOQC can be implemented using a constant-size device with modest physical depth, and that percolation can be exploited using simple pathfinding strategies without the need for high-complexity algorithms.

Proposal for demonstration of long-range cluster state entanglement in the presence of photon loss

Directory of Open Access Journals (Sweden)

Thomas Nutz

2017-06-01

Full Text Available Photonic cluster states are a crucial resource for optical quantum computing. Recently a quantum dot single photon source has been demonstrated to produce strings of single photons in a small linear cluster state. Sources of this kind could produce much larger cluster states, but high photon loss rates make it impossible to characterize the entanglement generated by quantum state tomography. We present a benchmarking method for such sources that can be used to demonstrate useful long-range entanglement with currently available collection/detection efficiencies below 1%. The measurement of the polarization state of single photons in different bases can provide an estimate for the three-qubit correlation function ⟨ZXZ⟩. This value constrains correlations spanning more than three qubits, which in turn provide a lower bound for the localizable entanglement between any two qubits in the large state produced by the source. Finite localizable entanglement can be established by demonstrating ⟨ZXZ⟩>23. This result enables photonic experiments demonstrating computationally useful entanglement with currently available technology.

Protocol for generating multiphoton entangled states from quantum dots in the presence of nuclear spin fluctuations

DEFF Research Database (Denmark)

Denning, Emil Vosmar; Iles-Smith, Jake; McCutcheon, Dara P. S.

2017-01-01

Multiphoton entangled states are a crucial resource for many applications inquantum information science. Semiconductor quantum dots offer a promising route to generate such states by mediating photon-photon correlations via a confinedelectron spin, but dephasing caused by the host nuclear spin...... environment typically limits coherence (and hence entanglement) between photons to the spin T2* time of a few nanoseconds. We propose a protocol for the deterministic generation of multiphoton entangled states that is inherently robust against the dominating slow nuclear spin environment fluctuations, meaning...... that coherence and entanglement is instead limited only by the much longer spin T2 time of microseconds. Unlike previous protocols, the present schemeallows for the generation of very low error probability polarisation encoded three-photon GHZ states and larger entangled states, without the need for spin echo...

Quantum optical measurement with tripartite entangled photons generated by triple parametric down-conversion

Science.gov (United States)

Cho, Minhaeng

2018-05-01

Parametric down-conversion is a second-order nonlinear optical process annihilating a pump photon and creating a pair of photons in the signal and idler modes. Then, by using two parametric down-converters and introducing a path indistinguishability for the two generated idler modes, a quantum coherence between two conjugate signal beams can be induced. Such a double spontaneous or stimulated parametric down-conversion scheme has been used to demonstrate quantum spectroscopy and imaging with undetected idler photons via measuring one-photon interference between their correlated signal beams. Recently, we considered another quantum optical measurement scheme utilizing W-type tripartite entangled signal photons that can be generated by employing three spontaneous parametric down-conversion crystals and by inducing coherences or path-indistinguishabilities between their correlated idler beams and between quantum vacuum fields. Here, we consider an extended triple stimulated parametric down-conversion scheme for quantum optical measurement of sample properties with undetected idler and photons. Noting the real effect of vacuum field indistinguishability on the fringe visibility as well as the role of zero-point field energy in the interferometry, we show that this scheme is an ideal and efficient way to create a coherent state of W-type entangled signal photons. We anticipate that this scheme would be of critical use in further developing quantum optical measurements in spectroscopy and microscopy with undetected photons.

Quantum optical measurement with tripartite entangled photons generated by triple parametric down-conversion.

Science.gov (United States)

Cho, Minhaeng

2018-05-14

Parametric down-conversion is a second-order nonlinear optical process annihilating a pump photon and creating a pair of photons in the signal and idler modes. Then, by using two parametric down-converters and introducing a path indistinguishability for the two generated idler modes, a quantum coherence between two conjugate signal beams can be induced. Such a double spontaneous or stimulated parametric down-conversion scheme has been used to demonstrate quantum spectroscopy and imaging with undetected idler photons via measuring one-photon interference between their correlated signal beams. Recently, we considered another quantum optical measurement scheme utilizing W-type tripartite entangled signal photons that can be generated by employing three spontaneous parametric down-conversion crystals and by inducing coherences or path-indistinguishabilities between their correlated idler beams and between quantum vacuum fields. Here, we consider an extended triple stimulated parametric down-conversion scheme for quantum optical measurement of sample properties with undetected idler and photons. Noting the real effect of vacuum field indistinguishability on the fringe visibility as well as the role of zero-point field energy in the interferometry, we show that this scheme is an ideal and efficient way to create a coherent state of W-type entangled signal photons. We anticipate that this scheme would be of critical use in further developing quantum optical measurements in spectroscopy and microscopy with undetected photons.

Four-State Continuous-Variable Quantum Key Distribution with Photon Subtraction

Science.gov (United States)

Li, Fei; Wang, Yijun; Liao, Qin; Guo, Ying

2018-06-01

Four-state continuous-variable quantum key distribution (CVQKD) is one of the discretely modulated CVQKD which generates four nonorthogonal coherent states and exploits the sign of the measured quadrature of each state to encode information rather than uses the quadrature \\hat {x} or \\hat {p} itself. It has been proven that four-state CVQKD is more suitable than Gaussian modulated CVQKD in terms of transmission distance. In this paper, we propose an improved four-state CVQKD using an non-Gaussian operation, photon subtraction. A suitable photon-subtraction operation can be exploited to improve the maximal transmission of CVQKD in point-to-point quantum communication since it provides a method to enhance the performance of entanglement-based (EB) CVQKD. Photon subtraction not only can lengthen the maximal transmission distance by increasing the signal-to-noise rate but also can be easily implemented with existing technologies. Security analysis shows that the proposed scheme can lengthen the maximum transmission distance. Furthermore, by taking finite-size effect into account we obtain a tighter bound of the secure distance, which is more practical than that obtained in the asymptotic limit.

Engineering photonic density of states using metamaterials

DEFF Research Database (Denmark)

Jacob, Z.; Kim, J.Y.; Naik, G.V.

2010-01-01

The photonic density of states (PDOS), like its electronic counterpart, is one of the key physical quantities governing a variety of phenomena and hence PDOS manipulation is the route to new photonic devices. The PDOS is conventionally altered by exploiting the resonance within a device such as a......The photonic density of states (PDOS), like its electronic counterpart, is one of the key physical quantities governing a variety of phenomena and hence PDOS manipulation is the route to new photonic devices. The PDOS is conventionally altered by exploiting the resonance within a device...... such as a microcavity or a bandgap structure like a photonic crystal. Here we show that nanostructured metamaterials with hyperbolic dispersion can dramatically enhance the photonic density of states paving the way for metamaterial-based PDOS engineering....

Conditional generation of the Greenberger-Horne-Zeilinger state of four distant atoms via cavity decay

International Nuclear Information System (INIS)

Zou, XuBo; Pahlke, K.; Mathis, W.

2003-01-01

We propose a scheme to generate a four-particle Greenberger-Horne-Zeilinger (GHZ) state of distant atoms that are trapped separately in leaky cavities. This scheme uses cavity decay to inject photons into a setup of optical devices that consist of a symmetric series of beam splitters and photon detectors. Photon detection on the output modes of the beam splitters projects the atom-cavity-system state onto the GHZ state. It is briefly pointed out that this scheme can be extended to generate GHZ states of 4m atoms

Photon statistical properties of photon-added two-mode squeezed coherent states

International Nuclear Information System (INIS)

Xu Xue-Fen; Wang Shuai; Tang Bin

2014-01-01

We investigate photon statistical properties of the multiple-photon-added two-mode squeezed coherent states (PA-TMSCS). We find that the photon statistical properties are sensitive to the compound phase involved in the TMSCS. Our numerical analyses show that the photon addition can enhance the cross-correlation and anti-bunching effects of the PA-TMSCS. Compared with that of the TMSCS, the photon number distribution of the PA-TMSCS is modulated by a factor that is a monotonically increasing function of the numbers of adding photons to each mode; further, that the photon addition essentially shifts the photon number distribution. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Photon final states at the Tevatron

Energy Technology Data Exchange (ETDEWEB)

Campanelli, Mario; /University Coll. London

2008-04-01

The authors present here several recent measurements involving associate production of photons and jets at the Tevatron. In particular, inclusive photon + met from D0, and photon + b-jets and photon + b-jet + leptons + MET from CDF are described in some detail. These measurements offer a good test of QCD predictions in rather complex final states.

Generation of Fourier-transform-limited heralded single photons

International Nuclear Information System (INIS)

U'Ren, Alfred B.; Jeronimo-Moreno, Yasser; Garcia-Gracia, Hipolito

2007-01-01

In this paper we study the spectral (temporal) properties of heralded single photon wave packets, triggered by the detection of an idler photon in the process of parametric down conversion. The generated single photons are studied within the framework of the chronocyclic Wigner function, from which the single photon spectral width and temporal duration can be computed. We derive specific conditions on the two-photon joint spectral amplitude which result in both pure and Fourier-transform-limited heralded single photons. Likewise, we present specific source geometries which lead to the fulfillment of these conditions and show that one of these geometries leads, for a given pump bandwidth, to the temporally shortest possible heralded single photon wave packets

Two-photon spin generation and detection

Energy Technology Data Exchange (ETDEWEB)

Miah, M Idrish, E-mail: m.miah@griffith.edu.a [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)

2009-02-21

A time- and polarization-resolved two-photon pump-probe investigation is performed in lightly doped GaAs. We generate spin-polarized electrons in bulk GaAs at various temperatures using right-circularly polarized two-photon excitation and detect them by probing the spin-dependent transmission of the sample. The spin polarization (P) of conduction band electrons, as measured using probe pulses with the same (right) and opposite (left) circular polarization, is measured in dependences of pump-probe delay ({Delta}t), lattice temperature (T{sub L}), doping density (n) as well as of the excess photon energy {Delta}E{sub 2{omega}}= {h_bar}2{omega} - E{sub g}, where E{sub g} is the band gap energy. P is found to be decayed with {Delta}t and enhanced with the decrease in T{sub L} or the increase in n. It is also found that P decreases with the increase in {Delta}E{sub 2{omega}}and depolarizes rapidly for {Delta}E{sub 2{omega}}> {Delta}E{sub SO}, where {Delta}E{sub SO} is the spin-orbit splitting energy. The results demonstrate that due to a much longer absorption depth highly polarized spins can be generated optically by two-photon pumping of bulk semiconductors.

Single-photon generator for optical telecommunication wavelength

International Nuclear Information System (INIS)

Usuki, T; Sakuma, Y; Hirose, S; Takemoto, K; Yokoyama, N; Miyazawa, T; Takatsu, M; Arakawa, Y

2006-01-01

We report on the generation of single-photon pulses from a single InAs/InP quantum dot in telecommunication bands (1.3-1.55 μm: higher transmittance through an optical fiber). First we prepared InAs quantum dots on InP (0 0 1) substrates in a low-pressure MOCVD by using a so-called InP 'double-cap' procedure. The quantum dots have well-controlled photo emission wavelength in the telecommunication bands. We also developed a single-photon emitter in which quantum dots were embedded. Numerical simulation designed the emitter to realize efficient injection of the emitted photons into a single-mode optical fiber. Using a Hanbury-Brown and Twiss technique has proved that the photons through the fiber were single photons

Multiple electron generation in a sea of electronic states

Science.gov (United States)

Witzel, Wayne; Shabaev, Andrew; Efros, Alexander; Hellberg, Carl; Verne, Jacobs

2009-03-01

In traditional bulk semiconductor photovoltaics (PVs), each photon may excite a single electron-hole, wasting excess energy beyond the band-gap as heat. In nanocrystals, multiple excitons can be generated from a single photon, enhancing the PV current. Multiple electron generation (MEG) may result from Coulombic interactions of the confined electrons. Previous investigations have been based on incomplete or over-simplified electronic-state representations. We present results of quantum simulations that include hundreds of thousands of configuration states and show how the complex dynamics, even in a closed electronic system, yields a saturated MEG effect on a femtosecond timescale. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

State preparation and detector effects in quantum measurements of rotation with circular polarization-entangled photons and photon counting

Science.gov (United States)

Cen, Longzhu; Zhang, Zijing; Zhang, Jiandong; Li, Shuo; Sun, Yifei; Yan, Linyu; Zhao, Yuan; Wang, Feng

2017-11-01

Circular polarization-entangled photons can be used to obtain an enhancement of the precision in a rotation measurement. In this paper, the method of entanglement transformation is used to produce NOON states in circular polarization from a readily generated linear polarization-entangled photon source. Detection of N -fold coincidences serves as the postselection and N -fold superoscillating fringes are obtained simultaneously. A parity strategy and conditional probabilistic statistics contribute to a better fringe, saturating the angle sensitivity to the Heisenberg limit. The impact of imperfect state preparation and detection is discussed both separately and jointly. For the separated case, the influence of each system imperfection is pronounced. For the joint case, the feasibility region for surpassing the standard quantum limit is given. Our work pushes the state preparation of circular polarization-entangled photons to the same level as that in the case of linear polarization. It is also confirmed that entanglement can be transformed into different frames for specific applications, serving as a useful scheme for using entangled sources.

Generating entangled state of Bose-Einstein condensate using electromagnetically induced transparency

Science.gov (United States)

Li, Song-Song

2018-01-01

We put forward a scheme on how to generate entangled state of Bose-Einstein condensate (BEC) using electromagnetically induced transparency (EIT). It is shown that we can rapidly generate the entangled state in the dynamical process and the entangled state maintained a long time interval. It is also shown that the better entangled state can be generated by decreasing coupling strengths of two classical laser fields, increasing two-photon detuning and total number of atoms.

Decoherence and Fidelity in Teleportation of Coherent Photon-Added Two-Mode Squeezed Thermal States

Science.gov (United States)

Li, Heng-Mei; Yuan, Hong-Chun; Wan, Zhi-Long; Wang, Zhen

2018-04-01

We theoretically introduce a kind of non-Gaussian entangled resources, i.e., coherent photon-added two-mode squeezed thermal states (CPA-TMSTS), by successively performing coherent photon addition operation to the two-mode squeezed thermal states. The normalization factor related to bivariate Hermite polynomials is obtained. Based upon it, the nonclassicality and decoherence process are analyzed by virtue of the Wigner function. It is shown that the coherent photon addition operation is an effective way in generating partial negative values of Wigner function, which clearly manifests the nonclassicality and non-Gaussianity of the target states. Additionally, the fidelity in teleporting coherent states using CPA-TMSTS as entangled resource is quantified both analytically and numerically. It is found that the CPA-TMSTS is an entangled resource of high-efficiency and high-fidelity in quantum teleportation.

Single-photon two-qubit entangled states: Preparation and measurement

International Nuclear Information System (INIS)

Kim, Yoon-Ho

2003-01-01

We implement experimentally a deterministic method to prepare and measure the so-called single-photon two-qubit entangled states or single-photon Bell states, in which the polarization and the spatial modes of a single photon each represent a quantum bit. All four single-photon Bell states can be easily prepared and measured deterministically using linear optical elements alone. We also discuss how this method can be used for the recently proposed single-photon two-qubit quantum cryptography scheme

The generation of the Greenberger-Horne-Zeilinger state of four distant atoms conditioned on cavity decay

International Nuclear Information System (INIS)

Pahlke, Kai; Zou Xubo; Mathis, Wolfgang

2004-01-01

We show a way to use an optical device set-up to generate the four-particle Greenberger-Horne-Zeilinger (GHZ) state of atoms, which are trapped separately in leaky cavities. Based on cavity decay, photons are transferred from the atom-cavity systems to a symmetric series of beam splitters and photon detectors. The events of photon detection on the output modes of the beam splitters project the state of the atom-cavity systems onto the GHZ state. It is briefly pointed out how this scheme can be extended to generate GHZ states of 4m atoms

Dynamically tunable interface states in 1D graphene-embedded photonic crystal heterostructure

Science.gov (United States)

Huang, Zhao; Li, Shuaifeng; Liu, Xin; Zhao, Degang; Ye, Lei; Zhu, Xuefeng; Zang, Jianfeng

2018-03-01

Optical interface states exhibit promising applications in nonlinear photonics, low-threshold lasing, and surface-wave assisted sensing. However, the further application of interface states in configurable optics is hindered by their limited tunability. Here, we demonstrate a new approach to generate dynamically tunable and angle-resolved interface states using graphene-embedded photonic crystal (GPC) heterostructure device. By combining the GPC structure design with in situ electric doping of graphene, a continuously tunable interface state can be obtained and its tuning range is as wide as the full bandgap. Moreover, the exhibited tunable interface states offer a possibility to study the correspondence between space and time characteristics of light, which is beyond normal incident conditions. Our strategy provides a new way to design configurable devices with tunable optical states for various advanced optical applications such as beam splitter and dynamically tunable laser.

Elliptical quantum dots as on-demand single photons sources with deterministic polarization states

Energy Technology Data Exchange (ETDEWEB)

Teng, Chu-Hsiang; Demory, Brandon; Ku, Pei-Cheng, E-mail: peicheng@umich.edu [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48105 (United States); Zhang, Lei; Hill, Tyler A.; Deng, Hui [Department of Mechanical Engineering, University of Michigan, 2350 Hayward St., Ann Arbor, Michigan 48105 (United States)

2015-11-09

In quantum information, control of the single photon's polarization is essential. Here, we demonstrate single photon generation in a pre-programmed and deterministic polarization state, on a chip-scale platform, utilizing site-controlled elliptical quantum dots (QDs) synthesized by a top-down approach. The polarization from the QD emission is found to be linear with a high degree of linear polarization and parallel to the long axis of the ellipse. Single photon emission with orthogonal polarizations is achieved, and the dependence of the degree of linear polarization on the QD geometry is analyzed.

Heralded generation of a micro-macro entangled state

DEFF Research Database (Denmark)

Andersen, Ulrik Lund; Neergaard-Nielsen, Jonas Schou

2013-01-01

Using different optical setups based on squeezed state and photon subtraction we show how optical entanglement between a macroscopic and a microscopic state-the so-called Schro¨dinger cat state or micro-macro state-can be generated. The entangled state is heralded and is thus produced a priori....... Furthermore, we show that the state can be used to map a microscopic qubit onto a macroscopic one thereby linking a qubit processor with a qumode processor....

Quantum key distribution with a single photon from a squeezed coherent state

International Nuclear Information System (INIS)

Matsuoka, Masahiro; Hirano, Takuya

2003-01-01

Squeezing of the coherent state by optical parametric amplifier is shown to efficiently produce single-photon states with reduced multiphoton probabilities compared with the weak coherent light. It can be a better source for a longer-distance quantum key distribution and also for other quantum optical experiments. The necessary condition for a secure quantum key distribution given by Brassard et al. is analyzed as functions of the coherent-state amplitude and squeeze parameter. Similarly, the rate of the gained secure bits G after error correction and privacy amplification given by Luetkenhaus is calculated. Compared with the weak coherent light, it is found that G is about ten times larger and its high level continues on about two times longer distance. By improvement of the detector efficiency it is shown that the distance extends further. Measurement of the intensity correlation function and the relation to photon antibunching are discussed for the experimental verification of the single-photon generation

Photon-number discrimination without a photon counter and its application to reconstructing non-Gaussian states

International Nuclear Information System (INIS)

Chrzanowski, H. M.; Bernu, J.; Sparkes, B. M.; Hage, B.; Lam, P. K.; Symul, T.; Lund, A. P.; Ralph, T. C.

2011-01-01

The nonlinearity of a conditional photon-counting measurement can be used to ''de-Gaussify'' a Gaussian state of light. Here we present and experimentally demonstrate a technique for photon-number resolution using only homodyne detection. We then apply this technique to inform a conditional measurement, unambiguously reconstructing the statistics of the non-Gaussian one- and two-photon-subtracted squeezed vacuum states. Although our photon-number measurement relies on ensemble averages and cannot be used to prepare non-Gaussian states of light, its high efficiency, photon-number-resolving capabilities, and compatibility with the telecommunications band make it suitable for quantum-information tasks relying on the outcomes of mean values.

Theory of the effect of third-harmonic generation on three-photon resonantly enhanced multiphoton ionization in focused beams

International Nuclear Information System (INIS)

Payne, M.G.; Garrett, W.R.

1983-01-01

Multiphoton ionization in the region near a three-photon resonance is treated for focused, plane-polarized Gaussian beams with diffraction-limited beam divergence. In this situation, a third-harmonic field is generated within the laser beam. At, and very near, three-photon resonance the driving rate for the upper-state probability amplitude due to one-photon absorption of third-harmonic light becomes nearly equal to the corresponding three-photon rate due to the laser field, but these effects are 180 0 out of phase. As a consequence of this cancellation between two pumping terms, the three-photon resonance line essentially disappears at moderate concentrations and the observed ionization has a line shape that is close to the phase-matching curve for third-harmonic generation. The ionization signal, near but not on the resonance, is due almost entirely to absorption of third-harmonic photons plus other laser photons; three-photon resonantly enhanced multiphoton ionization by the laser is much weaker. This is particularly true on the blue side of the three-photon resonance at detunings where phase matching occurs. The problem is treated quite generally with predictions of the full line shape for n-photon ionization and third-harmonic light generation near three-photon resonance, including the rather strong influences of positively dispersive buffer gases. We also show that the cancellation between the one-photon and the three-photon process is partially spoiled in the presence of a counterpropagating beam at the same frequency

Quantum random-number generator based on a photon-number-resolving detector

International Nuclear Information System (INIS)

Ren Min; Wu, E; Liang Yan; Jian Yi; Wu Guang; Zeng Heping

2011-01-01

We demonstrated a high-efficiency quantum random number generator which takes inherent advantage of the photon number distribution randomness of a coherent light source. This scheme was realized by comparing the photon flux of consecutive pulses with a photon number resolving detector. The random bit generation rate could reach 2.4 MHz with a system clock of 6.0 MHz, corresponding to a random bit generation efficiency as high as 40%. The random number files passed all the stringent statistical tests.

Complete Bell-state analysis for a single-photon hybrid entangled state

International Nuclear Information System (INIS)

Sheng Yu-Bo; Zhou Lan; Cheng Wei-Wen; Gong Long-Yan; Wang Lei; Zhao Sheng-Mei

2013-01-01

We propose a scheme capable of performing complete Bell-state analysis for a single-photon hybrid entangled state. Our single-photon state is encoded in both polarization and frequency degrees of freedom. The setup of the scheme is composed of polarizing beam splitters, half wave plates, frequency shifters, and independent wavelength division multiplexers, which are feasible using current technology. We also show that with this setup we can perform complete two-photon Bell-state analysis schemes for polarization degrees of freedom. Moreover, it can also be used to perform the teleportation scheme between different degrees of freedom. This setup may allow extensive applications in current quantum communications

Advanced optical components for next-generation photonic networks

Science.gov (United States)

Yoo, S. J. B.

2003-08-01

Future networks will require very high throughput, carrying dominantly data-centric traffic. The role of Photonic Networks employing all-optical systems will become increasingly important in providing scalable bandwidth, agile reconfigurability, and low-power consumptions in the future. In particular, the self-similar nature of data traffic indicates that packet switching and burst switching will be beneficial in the Next Generation Photonic Networks. While the natural conclusion is to pursue Photonic Packet Switching and Photonic Burst Switching systems, there are significant challenges in realizing such a system due to practical limitations in optical component technologies. Lack of a viable all-optical memory technology will continue to drive us towards exploring rapid reconfigurability in the wavelength domain. We will introduce and discuss the advanced optical component technologies behind the Photonic Packet Routing system designed and demonstrated at UC Davis. The system is capable of packet switching and burst switching, as well as circuit switching with 600 psec switching speed and scalability to 42 petabit/sec aggregated switching capacity. By utilizing a combination of rapidly tunable wavelength conversion and a uniform-loss cyclic frequency (ULCF) arrayed waveguide grating router (AWGR), the system is capable of rapidly switching the packets in wavelength, time, and space domains. The label swapping module inside the Photonic Packet Routing system containing a Mach-Zehnder wavelength converter and a narrow-band fiber Bragg-grating achieves all-optical label swapping with optical 2R (potentially 3R) regeneration while maintaining optical transparency for the data payload. By utilizing the advanced optical component technologies, the Photonic Packet Routing system successfully demonstrated error-free, cascaded, multi-hop photonic packet switching and routing with optical-label swapping. This paper will review the advanced optical component technologies

Photon-number discrimination without a photon counter and its application to reconstructing non-Gaussian states

Energy Technology Data Exchange (ETDEWEB)

Chrzanowski, H. M.; Bernu, J.; Sparkes, B. M.; Hage, B.; Lam, P. K.; Symul, T. [Centre for Quantum Computation and Communication Technology, Quantum Optics group, Department of Quantum Science, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Lund, A. P. [Centre for Quantum Computation and Communication Technology, Centre for Quantum Dynamics, Griffith University, Nathan QLD 4111 (Australia); Ralph, T. C. [Centre for Quantum Computation and Communication Technology, Department of Physics, University of Queensland, St. Lucia QLD 4072 (Australia)

2011-11-15

The nonlinearity of a conditional photon-counting measurement can be used to ''de-Gaussify'' a Gaussian state of light. Here we present and experimentally demonstrate a technique for photon-number resolution using only homodyne detection. We then apply this technique to inform a conditional measurement, unambiguously reconstructing the statistics of the non-Gaussian one- and two-photon-subtracted squeezed vacuum states. Although our photon-number measurement relies on ensemble averages and cannot be used to prepare non-Gaussian states of light, its high efficiency, photon-number-resolving capabilities, and compatibility with the telecommunications band make it suitable for quantum-information tasks relying on the outcomes of mean values.

Deterministic and robust generation of single photons from a single quantum dot with 99.5% indistinguishability using adiabatic rapid passage.

Science.gov (United States)

Wei, Yu-Jia; He, Yu-Ming; Chen, Ming-Cheng; Hu, Yi-Nan; He, Yu; Wu, Dian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

2014-11-12

Single photons are attractive candidates of quantum bits (qubits) for quantum computation and are the best messengers in quantum networks. Future scalable, fault-tolerant photonic quantum technologies demand both stringently high levels of photon indistinguishability and generation efficiency. Here, we demonstrate deterministic and robust generation of pulsed resonance fluorescence single photons from a single semiconductor quantum dot using adiabatic rapid passage, a method robust against fluctuation of driving pulse area and dipole moments of solid-state emitters. The emitted photons are background-free, have a vanishing two-photon emission probability of 0.3% and a raw (corrected) two-photon Hong-Ou-Mandel interference visibility of 97.9% (99.5%), reaching a precision that places single photons at the threshold for fault-tolerant surface-code quantum computing. This single-photon source can be readily scaled up to multiphoton entanglement and used for quantum metrology, boson sampling, and linear optical quantum computing.

New Generation of Superconducting Nanowire Single-Photon Detectors

Directory of Open Access Journals (Sweden)

Goltsman G.N.

2015-01-01

Full Text Available We present an overview of recent results for new generation of infrared and optical superconducting nanowire single-photon detectors (SNSPDs that has already demonstrated a performance that makes them devices-of-choice for many applications. SNSPDs provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, SNSPDs are also compatible with an integrated optical platform as a crucial requirement for applications in emerging quantum photonic technologies. By embedding SNSPDs in nanophotonic circuits we realize waveguide integrated single photon detectors which unite all desirable detector properties in a single device.

How random are random numbers generated using photons?

International Nuclear Information System (INIS)

Solis, Aldo; Angulo Martínez, Alí M; Ramírez Alarcón, Roberto; Cruz Ramírez, Hector; U’Ren, Alfred B; Hirsch, Jorge G

2015-01-01

Randomness is fundamental in quantum theory, with many philosophical and practical implications. In this paper we discuss the concept of algorithmic randomness, which provides a quantitative method to assess the Borel normality of a given sequence of numbers, a necessary condition for it to be considered random. We use Borel normality as a tool to investigate the randomness of ten sequences of bits generated from the differences between detection times of photon pairs generated by spontaneous parametric downconversion. These sequences are shown to fulfil the randomness criteria without difficulties. As deviations from Borel normality for photon-generated random number sequences have been reported in previous work, a strategy to understand these diverging findings is outlined. (paper)

Correlated Photon Pair Generation in Silicon Wire Waveguides at 1.5 μm

International Nuclear Information System (INIS)

Cheng Jie-Rong; Zhang Wei; Zhou Qiang; Feng Xue; Huang Yi-Dong; Peng Jiang-De

2010-01-01

Correlated photon pairs at 1.5μm are generated in a silicon wire waveguide (SWW) with a length of only 1.6mm. Experimental results show that the single-side count rates on both sides increase quadratically with pump light, indicating that photons are generated from the spontaneous four-wave mixing (SFWM) processes. The quantum correlation property of the generated photons is demonstrated by the ratio between coincident and accidental coincident count rates. The highest ratio measured at room temperature is to be about 19, showing that generated photon pairs have strong quantum correlation property and low noise. What is more, the wavelength correlation property of the coincident count is also measured to demonstrate the correlated photon pair generation. The experimental results demonstrate that SWWs have great potential in on-chip integrated low-noise correlated photon pair sources at 1.5 μm. (fundamental areas of phenomenology(including applications))

Quantum coherence generated by interference-induced state selectiveness

OpenAIRE

Garreau, Jean Claude

2001-01-01

The relations between quantum coherence and quantum interference are discussed. A general method for generation of quantum coherence through interference-induced state selection is introduced and then applied to `simple' atomic systems under two-photon transitions, with applications in quantum optics and laser cooling.

Solid-state single-photon emitters

Science.gov (United States)

Aharonovich, Igor; Englund, Dirk; Toth, Milos

2016-10-01

Single-photon emitters play an important role in many leading quantum technologies. There is still no 'ideal' on-demand single-photon emitter, but a plethora of promising material systems have been developed, and several have transitioned from proof-of-concept to engineering efforts with steadily improving performance. Here, we review recent progress in the race towards true single-photon emitters required for a range of quantum information processing applications. We focus on solid-state systems including quantum dots, defects in solids, two-dimensional hosts and carbon nanotubes, as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. We consider the main challenges and key advantages of each platform, with a focus on scalable on-chip integration and fabrication of identical sources on photonic circuits.

From Three-Photon Greenberger-Horne-Zeilinger States to Ballistic Universal Quantum Computation.

Science.gov (United States)

Gimeno-Segovia, Mercedes; Shadbolt, Pete; Browne, Dan E; Rudolph, Terry

2015-07-10

Single photons, manipulated using integrated linear optics, constitute a promising platform for universal quantum computation. A series of increasingly efficient proposals have shown linear-optical quantum computing to be formally scalable. However, existing schemes typically require extensive adaptive switching, which is experimentally challenging and noisy, thousands of photon sources per renormalized qubit, and/or large quantum memories for repeat-until-success strategies. Our work overcomes all these problems. We present a scheme to construct a cluster state universal for quantum computation, which uses no adaptive switching, no large memories, and which is at least an order of magnitude more resource efficient than previous passive schemes. Unlike previous proposals, it is constructed entirely from loss-detecting gates and offers a robustness to photon loss. Even without the use of an active loss-tolerant encoding, our scheme naturally tolerates a total loss rate ∼1.6% in the photons detected in the gates. This scheme uses only 3 Greenberger-Horne-Zeilinger states as a resource, together with a passive linear-optical network. We fully describe and model the iterative process of cluster generation, including photon loss and gate failure. This demonstrates that building a linear-optical quantum computer needs to be less challenging than previously thought.

Practical single-photon-assisted remote state preparation with non-maximally entanglement

Science.gov (United States)

Wang, Dong; Huang, Ai-Jun; Sun, Wen-Yang; Shi, Jia-Dong; Ye, Liu

2016-08-01

Remote state preparation (RSP) and joint remote state preparation (JRSP) protocols for single-photon states are investigated via linear optical elements with partially entangled states. In our scheme, by choosing two-mode instances from a polarizing beam splitter, only the sender in the communication protocol needs to prepare an ancillary single-photon and operate the entanglement preparation process in order to retrieve an arbitrary single-photon state from a photon pair in partially entangled state. In the case of JRSP, i.e., a canonical model of RSP with multi-party, we consider that the information of the desired state is split into many subsets and in prior maintained by spatially separate parties. Specifically, with the assistance of a single-photon state and a three-photon entangled state, it turns out that an arbitrary single-photon state can be jointly and remotely prepared with certain probability, which is characterized by the coefficients of both the employed entangled state and the target state. Remarkably, our protocol is readily to extend to the case for RSP and JRSP of mixed states with the all optical means. Therefore, our protocol is promising for communicating among optics-based multi-node quantum networks.

Review of Microwave Photonics Technique to Generate the Microwave Signal by Using Photonics Technology

Science.gov (United States)

Raghuwanshi, Sanjeev Kumar; Srivastav, Akash

2017-12-01

Microwave photonics system provides high bandwidth capabilities of fiber optic systems and also contains the ability to provide interconnect transmission properties, which are virtually independent of length. The low-loss wide bandwidth capability of optoelectronic systems makes them attractive for the transmission and processing of microwave signals, while the development of high-capacity optical communication systems has required the use of microwave techniques in optical transmitters and receivers. These two strands have led to the development of the research area of microwave photonics. So, we can considered microwave photonics as the field that studies the interaction between microwave and optical waves for applications such as communications, radars, sensors and instrumentations. In this paper we have thoroughly reviewed the microwave generation techniques by using photonics technology.

Knot Undulator to Generate Linearly Polarized Photons with Low on-Axis Power Density

International Nuclear Information System (INIS)

Qiao, S.

2009-01-01

Heat load on beamline optics is a serious problem to generate pure linearly polarized photons in the third generation synchrotron radiation facilities. For permanent magnet undulators, this problem can be overcome by a figure-8 operating mode. But there is still no good method to tackle this problem for electromagnetic elliptical undulators. Here, a novel operating mode is suggested, which can generate pure linearly polarized photons with very low on-axis heat load. Also the available minimum photon energy of linearly polarized photons can be extended much by this method.

High-dimensional quantum key distribution with the entangled single-photon-added coherent state

Energy Technology Data Exchange (ETDEWEB)

Wang, Yang [Zhengzhou Information Science and Technology Institute, Zhengzhou, 450001 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Bao, Wan-Su, E-mail: 2010thzz@sina.com [Zhengzhou Information Science and Technology Institute, Zhengzhou, 450001 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Bao, Hai-Ze; Zhou, Chun; Jiang, Mu-Sheng; Li, Hong-Wei [Zhengzhou Information Science and Technology Institute, Zhengzhou, 450001 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2017-04-25

High-dimensional quantum key distribution (HD-QKD) can generate more secure bits for one detection event so that it can achieve long distance key distribution with a high secret key capacity. In this Letter, we present a decoy state HD-QKD scheme with the entangled single-photon-added coherent state (ESPACS) source. We present two tight formulas to estimate the single-photon fraction of postselected events and Eve's Holevo information and derive lower bounds on the secret key capacity and the secret key rate of our protocol. We also present finite-key analysis for our protocol by using the Chernoff bound. Our numerical results show that our protocol using one decoy state can perform better than that of previous HD-QKD protocol with the spontaneous parametric down conversion (SPDC) using two decoy states. Moreover, when considering finite resources, the advantage is more obvious. - Highlights: • Implement the single-photon-added coherent state source into the high-dimensional quantum key distribution. • Enhance both the secret key capacity and the secret key rate compared with previous schemes. • Show an excellent performance in view of statistical fluctuations.

High-dimensional quantum key distribution with the entangled single-photon-added coherent state

International Nuclear Information System (INIS)

Wang, Yang; Bao, Wan-Su; Bao, Hai-Ze; Zhou, Chun; Jiang, Mu-Sheng; Li, Hong-Wei

2017-01-01

High-dimensional quantum key distribution (HD-QKD) can generate more secure bits for one detection event so that it can achieve long distance key distribution with a high secret key capacity. In this Letter, we present a decoy state HD-QKD scheme with the entangled single-photon-added coherent state (ESPACS) source. We present two tight formulas to estimate the single-photon fraction of postselected events and Eve's Holevo information and derive lower bounds on the secret key capacity and the secret key rate of our protocol. We also present finite-key analysis for our protocol by using the Chernoff bound. Our numerical results show that our protocol using one decoy state can perform better than that of previous HD-QKD protocol with the spontaneous parametric down conversion (SPDC) using two decoy states. Moreover, when considering finite resources, the advantage is more obvious. - Highlights: • Implement the single-photon-added coherent state source into the high-dimensional quantum key distribution. • Enhance both the secret key capacity and the secret key rate compared with previous schemes. • Show an excellent performance in view of statistical fluctuations.

Generation of Symmetric Dicke States of Remote Qubits with Linear Optics

International Nuclear Information System (INIS)

Thiel, C.; Zanthier, J. von; Bastin, T.; Solano, E.; Agarwal, G. S.

2007-01-01

We propose a method for generating all symmetric Dicke states, either in the long-lived internal levels of N massive particles or in the polarization degrees of freedom of photonic qubits, using linear optical tools only. By means of a suitable multiphoton detection technique, erasing Welcher-Weg information, our proposed scheme allows the generation and measurement of an important class of entangled multiqubit states

Laser generation in opal-like single-crystal and heterostructure photonic crystals

Science.gov (United States)

Kuchyanov, A. S.; Plekhanov, A. I.

2016-11-01

This study describes the laser generation of a 6Zh rhodamine in artificial opals representing single-crystal and heterostructure films. The spectral and angular properties of emission and the threshold characteristics of generation are investigated. In the case where the 6Zh rhodamine was in a bulk opal, the so-called random laser generation was observed. In contrast to this, the laser generation caused by a distributed feedback inside the structure of the photonic bandgap was observed in photonic-crystal opal films.

Parameterization and generation of photon-induced K cross-sections

International Nuclear Information System (INIS)

Bansal, Meenakshi; Mittal, Raj

2010-01-01

Theoretical K-shell photoionization and K X-ray fluorescence (K XRF) cross sections have been fitted empirically in polynomials of photon energy E and atomic number Z. This has been used to develop a computer code KCSPIF to generate K-shell photo-ionization and K XRF cross-sections for any element in the range 5≤Z≤95 and for photon energies, above K-edge-1500 keV, when only the atomic number and photon energy are supplied as the input.

Photonic design for efficient solid state energy conversion

Science.gov (United States)

Agrawal, Mukul

The efficiency of conversion between electrical and photonic energy in optoelectronic devices such as light-emitting diodes, photodetectors and solar cells is strongly affected by the photonic modes supported by the device structure. In this thesis, we show how tuning of the local photon density of states in subwavelength structures can be used to optimize device performance. The first part of the thesis is focused on organic light emitting diodes (OLEDs), a candidate technology for next-generation displays and solid-state lighting. An important unsolved problem in OLEDs is to ensure that a significant fraction of photons emitted by the organic emissive layer couple out of the device structure instead of remaining trapped in the device. It is shown using modeling and experiments that optimized non-periodic dielectric multilayer stacks can significantly increase the photon outcoupling while maintaining display quality brightness uniformity over the viewing cone. In the second part, we discuss the theoretical limits to broadband light harvesting in photovoltaic cells. First, it is shown that the extent to which one-dimensional optical cavities can be used to enhance light absorption over a broad spectral range is limited by the requirement that the cavity mirrors have a causal response. This result is used as a guide to design practical dielectric structures that enhance light harvesting in planar thin-film organic solar cells. Finally, we consider the enhancement of optical absorption in two- and three-dimensional structures in which incident light is scattered into quasi-trapped modes for more effective utilization of solar radiation. It is shown that there is an upper bound to the degree to which optical absorption can be enhanced that is identical to the limit found in the geometric optics regime. Rigorous optical simulations are used to show that an optical structure consisting of a two-dimensional array of inverted pyramids comes close to this limit. Before

Preparation and purification of four-photon Greenberger–Horne–Zeilinger state

International Nuclear Information System (INIS)

He, Ying-Qiu; Ding, Dong; Yan, Feng-Li; Gao, Ting

2015-01-01

We present an efficient scheme for the preparing and purifying of the four-photon Greenberger–Horne–Zeilinger (GHZ) state based on linear optics and postselection. First, we describe how to create a four-photon GHZ state in both polarization and spatial degrees of freedom from two pairs. Moreover, in the presence of depolarization noise our scheme is capable of purifying the desired state. In the regime of weak nonlinearity we design an indirect photon number-resolving detection to distinguish two states of the two pairs. At last, a fourfold coincidence detector click indicates the creation of a polarization-entangled four-photon GHZ state. (paper)

Second harmonic generation from photonic structured GaN nanowalls

Energy Technology Data Exchange (ETDEWEB)

Soya, Takahiro; Inose, Yuta; Kunugita, Hideyuki; Ema, Kazuhiro; Yamano, Kouji; Kikuchi, Akihiko; Kishino, Katsumi, E-mail: t-soya@sophia.ac.j [Department of Engineering and Applied Sciences, Sophia University 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554 (Japan)

2009-11-15

We observed large enhancement of reflected second harmonic generation (SHG) using the one-dimensional photonic effect in regularly arranged InGaN/GaN single-quantum-well nanowalls. Using the effect when both fundamental and SH resonate with the photonic mode, we obtained enhancement of about 40 times compared with conditions far from resonance.

Three-photon resonances due to autoionizing states in calcium

Energy Technology Data Exchange (ETDEWEB)

Zawadzka, A.; Dygdala, R.S.; Raczynski, A.; Zaremba, J.; Kobus, J. [Instytut Fizyki, Uniwersytet M Kopernika w Toruniu, Torun (Poland)

2002-04-28

In the present study we have investigated three-photon ionization in Ca in which autoionizing states are engaged. The two-photon resonant process (from the Ca ground state 4s{sup 2} {sup 1}S{sub 0}) occurred through or at least in the vicinity of one of the following states: 4s4d {sup 1}D{sub 2}, 4p{sup 2} {sup 3}P{sub 2}, 4s6s {sup 1}S{sub 0}, 4p{sup 2} {sup 1}D{sub 2} and 4p{sup 2} {sup 1}S{sub 0}, with the third photon either reaching the continuum directly or one of the autoionizing states. The three-photon resonant transitions to 3dmp, mf: {sup 1}P{sub 1}, {sup 3}P{sub 1} and {sup 3}D{sub 1} autoionizing states for m up to 21 have been observed. Some of the autoionizing resonances which we have found had not been observed before in a high-resolution one-photon absorption experiment (for J=1) and in multiphoton experiments (for J=3). We have compared the ionization signal as a function of the laser detuning and the laser intensity with theoretical curves obtained within a simple model (three-level atom + one-mode laser field). This gives information about the order of magnitude of the three-photon ionization probability through autoionizing states. (author)

Density of states functions for photonic crystals

International Nuclear Information System (INIS)

McPhedran, R.C.; McOrist, J.; Sterke, C.M. de; Nicorovici, N.A.; Botten, L.C.; Asatryan, A.A.

2004-01-01

We discuss density of states functions for photonic crystals, in the context of the two-dimensional problem for arrays of cylinders of arbitrary cross section. We introduce the mutual density of states (MDOS), and show that this function can be used to calculate both the local density of states (LDOS), which gives position information for emission of radiation from photonic crystals, and the spectral density of states (SDOS), which gives angular information. We establish the connection between MDOS, LDOS, SDOS and the conventional density of states, which depends only on frequency. We relate all four functions to the band structure and propagating states within the crystal, and give numerical examples of the relation between band structure and density of states functions

On-chip generation of high-dimensional entangled quantum states and their coherent control.

Science.gov (United States)

Kues, Michael; Reimer, Christian; Roztocki, Piotr; Cortés, Luis Romero; Sciara, Stefania; Wetzel, Benjamin; Zhang, Yanbing; Cino, Alfonso; Chu, Sai T; Little, Brent E; Moss, David J; Caspani, Lucia; Azaña, José; Morandotti, Roberto

2017-06-28

Optical quantum states based on entangled photons are essential for solving questions in fundamental physics and are at the heart of quantum information science. Specifically, the realization of high-dimensional states (D-level quantum systems, that is, qudits, with D > 2) and their control are necessary for fundamental investigations of quantum mechanics, for increasing the sensitivity of quantum imaging schemes, for improving the robustness and key rate of quantum communication protocols, for enabling a richer variety of quantum simulations, and for achieving more efficient and error-tolerant quantum computation. Integrated photonics has recently become a leading platform for the compact, cost-efficient, and stable generation and processing of non-classical optical states. However, so far, integrated entangled quantum sources have been limited to qubits (D = 2). Here we demonstrate on-chip generation of entangled qudit states, where the photons are created in a coherent superposition of multiple high-purity frequency modes. In particular, we confirm the realization of a quantum system with at least one hundred dimensions, formed by two entangled qudits with D = 10. Furthermore, using state-of-the-art, yet off-the-shelf telecommunications components, we introduce a coherent manipulation platform with which to control frequency-entangled states, capable of performing deterministic high-dimensional gate operations. We validate this platform by measuring Bell inequality violations and performing quantum state tomography. Our work enables the generation and processing of high-dimensional quantum states in a single spatial mode.

Applications of photon-in, photon-out spectroscopy with third-generation, synchrotron-radiation sources

International Nuclear Information System (INIS)

Lindle, D.W.; Perera, R.C.C.

1991-01-01

This report discusses the following topics: Mother nature's finest test probe; soft x-ray emission spectroscopy with high-brightness synchrotron radiation sources; anisotropy and polarization of x-ray emission from atoms and molecules; valence-hole fluorescence from molecular photoions as a probe of shape-resonance ionization: progress and prospects; structural biophysics on third-generation synchrotron sources; ultra-soft x-ray fluorescence-yield XAFS: an in situ photon-in, photon-out spectroscopy; and x-ray microprobe: an analytical tool for imaging elemental composition and microstructure

Effects of noninstantaneous nonlinear processes on photon-pair generation by spontaneous four-wave mixing

DEFF Research Database (Denmark)

Koefoed, Jacob Gade; Christensen, Jesper Bjerge; Rottwitt, Karsten

2017-01-01

We present a general model, based on a Hamiltonian approach, for the joint quantum state of photon pairs generated through pulsed spontaneous four-wave mixing, including nonlinear phase modulation and a finite material response time. For the case of a silica fiber, it is found that the pair......-production rate depends weakly on the waveguide temperature, due to higher-order Raman scattering events, and more strongly on pump-pair frequency detuning. From the analytical model, a numerical scheme is derived, based on the well-known split-step method. This scheme allows computation of joint states where......-dependent change in quantum-mechanical purity may be observed in silica. This shows that Raman scattering not only introduces noise, but can also drastically change the spectral correlations in photon pairs when pumped with short pulses....

Path entanglement of photons by non-local bunching

International Nuclear Information System (INIS)

Eisenberg, H.; Hodelin, J.; Khoury, G.; Bouwmeester, D.

2005-01-01

Full Text:Path entangled photon states can be used to overcome classical limits on the accuracy of interferometric measurements such as the diffraction limit. These states are superpositions of finding n photons in one out of two (or more) paths. Using stimulated parametric down-conversion, we propose and demonstrate a method for generating heralded multiphoton path entanglement, without applying post-selection. parametric down-conversion is relatively easy to produce compared to pure Fock states as demanded by other proposals. By a special coincidence detection at one down converted arm, the photons of the second arm non-locally bunch into the desired state. Entanglement in photon number is created between two polarization modes rather than two paths. A polarization beam-splitter and a 2 wave plate can translate between the two representations. The experimental generation of a two-photon path entangled state was detected by observing interference at half the photon wavelength. The scheme is generally extendable to higher photon numbers

Two-way QKD with single-photon-added coherent states

Science.gov (United States)

Miranda, Mario; Mundarain, Douglas

2017-12-01

In this work we present a two-way quantum key distribution (QKD) scheme that uses single-photon-added coherent states and displacement operations. The first party randomly sends coherent states (CS) or single-photon-added coherent states (SPACS) to the second party. The latter sends back the same state it received. Both parties decide which kind of states they are receiving by detecting or not a photon on the received signal after displacement operations. The first party must determine whether its sent and received states are equal; otherwise, the case must be discarded. We are going to show that an eavesdropper provided with a beam splitter gets the same information in any of the non-discarded cases. The key can be obtained by assigning 0 to CS and 1 to SPACS in the non-discarded cases. This protocol guarantees keys' security in the presence of a beam splitter attack even for states with a high number of photons in the sent signal. It also works in a lossy quantum channel, becoming a good bet for improving long-distance QKD.

On-Demand Microwave Generator of Shaped Single Photons

Science.gov (United States)

Forn-Díaz, P.; Warren, C. W.; Chang, C. W. S.; Vadiraj, A. M.; Wilson, C. M.

2017-11-01

We demonstrate the full functionality of a circuit that generates single microwave photons on demand, with a wave packet that can be modulated with a near-arbitrary shape. We achieve such a high tunability by coupling a superconducting qubit near the end of a semi-infinite transmission line. A dc superconducting quantum interference device shunts the line to ground and is employed to modify the spatial dependence of the electromagnetic mode structure in the transmission line. This control allows us to couple and decouple the qubit from the line, shaping its emission rate on fast time scales. Our decoupling scheme is applicable to all types of superconducting qubits and other solid-state systems and can be generalized to multiple qubits as well as to resonators.

Reconstruction of photon number conditioned states using phase randomized homodyne measurements

International Nuclear Information System (INIS)

Chrzanowski, H M; Assad, S M; Bernu, J; Hage, B; Lam, P K; Symul, T; Lund, A P; Ralph, T C

2013-01-01

We experimentally demonstrate the reconstruction of a photon number conditioned state without using a photon number discriminating detector. By using only phase randomized homodyne measurements, we reconstruct up to the three photon subtracted squeezed vacuum state. The reconstructed Wigner functions of these states show regions of pronounced negativity, signifying the non-classical nature of the reconstructed states. The techniques presented allow for complete characterization of the role of a conditional measurement on an ensemble of states, and might prove useful in systems where photon counting still proves technically challenging. (paper)

Nonlinear silicon photonics

Science.gov (United States)

Borghi, M.; Castellan, C.; Signorini, S.; Trenti, A.; Pavesi, L.

2017-09-01

Silicon photonics is a technology based on fabricating integrated optical circuits by using the same paradigms as the dominant electronics industry. After twenty years of fervid development, silicon photonics is entering the market with low cost, high performance and mass-manufacturable optical devices. Until now, most silicon photonic devices have been based on linear optical effects, despite the many phenomenologies associated with nonlinear optics in both bulk materials and integrated waveguides. Silicon and silicon-based materials have strong optical nonlinearities which are enhanced in integrated devices by the small cross-section of the high-index contrast silicon waveguides or photonic crystals. Here the photons are made to strongly interact with the medium where they propagate. This is the central argument of nonlinear silicon photonics. It is the aim of this review to describe the state-of-the-art in the field. Starting from the basic nonlinearities in a silicon waveguide or in optical resonator geometries, many phenomena and applications are described—including frequency generation, frequency conversion, frequency-comb generation, supercontinuum generation, soliton formation, temporal imaging and time lensing, Raman lasing, and comb spectroscopy. Emerging quantum photonics applications, such as entangled photon sources, heralded single-photon sources and integrated quantum photonic circuits are also addressed at the end of this review.

Voltage-Controlled Quantum Dynamics and Generation Entanglement between Two Separated Quantum-Dot Molecules Embedded in Photonic Crystal Cavities

International Nuclear Information System (INIS)

Cheng Mu-Tian; Song Yan-Yan; Ma Xiao-San; Wang Xia

2014-01-01

Voltage-controlled quantum dynamics of two quantum-dot molecules (QDMs) embedded in two separated photonic crystal cavities are theoretically investigated. We show numerically that generation of entangled states and population transfer between the two QDMs can be realized with the same coupling parameters. The effects of parameters deviation and dissipations on generation entangled states and populations transfer are also discussed. The results may be used for realization of new-type of solid state quantum devices and integrated electro-optical devices

Integrated Sources of Polarization Entangled Photon Pair States via Spontaneous Four-Wave Mixing in AlGaAs Waveguides

Science.gov (United States)

Kultavewuti, Pisek

Polarization-entangled photon pair states (PESs) are indispensable in several quantum protocols that should be implemented in an integrated photonic circuit for realizing a practical quantum technology. Preparing such states in integrated waveguides is in fact a challenge due to polarization mode dispersion. Unlike other conventional ways that are plagued with complications in fabrication or in state generation, in this thesis, the scheme based on parallel spontaneous four-wave mixing processes of two polarization waveguide modes is thoroughly studied in theory and experimentation for the polarization entanglement generation. The scheme in fact needs the modal dispersion, contradictory to the general perception, as revealed by a full quantum mechanical framework. The proper modal dispersion balances the effects of temporal walk-off and state factorizability. The study also shows that the popular standard platform such as a silicon-on-insulator wafer is far from suitable to implement the proposed simple generation technique. Proven by the quantum state tomography, the technique produces a highly-entangled state with a maximum concurrence of 0.97 +/- 0:01 from AlGaAs waveguides. In addition, the devices directly generated Bell states with an observed fidelity of 0.92 +/- 0:01 without any post-generation compensating steps. Novel suspended device structures, including their components, are then investigated numerically and experimentally characterized in pursuit of finding the geometry with the optimal dispersion property. The 700 nm x 1100 nm suspended rectangular waveguide is identified as the best geometry with a predicted maximum concurrence of 0.976 and a generation bandwidth of 3.3 THz. The suspended waveguide fabrication procedure adds about 15 dB/cm and 10 dB/cm of propagation loss to the TE and TM mode respectively, on top of the loss in corresponding full-cladding waveguides. Bridges, which structurally support the suspended waveguides, are optimized using

Conditional generation of arbitrary multimode entangled states of light with linear optics

International Nuclear Information System (INIS)

Fiurasek, J.; Massar, S.; Cerf, N. J.

2003-01-01

We propose a universal scheme for the probabilistic generation of an arbitrary multimode entangled state of light with finite expansion in Fock basis. The suggested setup involves passive linear optics, single-photon sources, strong coherent laser beams, and photodetectors with single-photon resolution. The efficiency of this setup may be greatly enhanced if, in addition, a quantum memory is available

Heralded noiseless amplification for single-photon entangled state with polarization feature

Science.gov (United States)

Wang, Dan-Dan; Jin, Yu-Yu; Qin, Sheng-Xian; Zu, Hao; Zhou, Lan; Zhong, Wei; Sheng, Yu-Bo

2018-03-01

Heralded noiseless amplification is a promising method to overcome the transmission photon loss in practical noisy quantum channel and can effectively lengthen the quantum communication distance. Single-photon entanglement is an important resource in current quantum communications. Here, we construct two single-photon-assisted heralded noiseless amplification protocols for the single-photon two-mode entangled state and single-photon three-mode W state, respectively, where the single-photon qubit has an arbitrary unknown polarization feature. After the amplification, the fidelity of the single-photon entangled state can be increased, while the polarization feature of the single-photon qubit can be well remained. Both the two protocols only require the linear optical elements, so that they can be realized under current experimental condition. Our protocols may be useful in current and future quantum information processing.

High-capacity quantum secure direct communication with two-photon six-qubit hyperentangled states

Science.gov (United States)

Wu, FangZhou; Yang, GuoJian; Wang, HaiBo; Xiong, Jun; Alzahrani, Faris; Hobiny, Aatef; Deng, FuGuo

2017-12-01

This study proposes the first high-capacity quantum secure direct communication (QSDC) with two-photon six-qubit hyper-entangled Bell states in two longitudinal momentum and polarization degrees of freedom (DOFs) of photon pairs, which can be generated using two 0.5 mm-thick type-I β barium borate crystal slabs aligned one behind the other and an eight-hole screen. The secret message can be independently encoded on the photon pairs with 64 unitary operations in all three DOFs. This protocol has a higher capacity than previous QSDC protocols because each photon pair can carry 6 bits of information, not just 2 or 4 bits. Our QSDC protocol decreases the influence of decoherence from environment noise by exploiting the decoy photons to check the security of the transmission of the first photon sequence. Compared with two-way QSDC protocols, our QSDC protocol is immune to an attack by an eavesdropper using Trojan horse attack strategies because it is a one-way quantum communication. The QSDC protocol has good applications in the future quantum communication because of all these features.

Quantum key distribution session with 16-dimensional photonic states

Science.gov (United States)

Etcheverry, S.; Cañas, G.; Gómez, E. S.; Nogueira, W. A. T.; Saavedra, C.; Xavier, G. B.; Lima, G.

2013-01-01

The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote parties, that can be used to extract a secret key. QKD with D-dimensional quantum channels provides security advantages that grow with increasing D. However, the vast majority of QKD implementations has been restricted to two dimensions. Here we demonstrate the feasibility of using higher dimensions for real-world quantum cryptography by performing, for the first time, a fully automated QKD session based on the BB84 protocol with 16-dimensional quantum states. Information is encoded in the single-photon transverse momentum and the required states are dynamically generated with programmable spatial light modulators. Our setup paves the way for future developments in the field of experimental high-dimensional QKD. PMID:23897033

Single-temporal-mode photon generation beyond the low-power regime

DEFF Research Database (Denmark)

McKinstrie, C. J.; Christensen, Jesper Bjerge; Rottwitt, Karsten

2017-01-01

Nondegenerate four-wave mixing in a strongly-birefringent fiber generates signal and idler photons that are associated with only one pair of temporal modes, for a wide range of pump powers. Nonlinear phase modulation degrades the heralded-signal purity only slightly.......Nondegenerate four-wave mixing in a strongly-birefringent fiber generates signal and idler photons that are associated with only one pair of temporal modes, for a wide range of pump powers. Nonlinear phase modulation degrades the heralded-signal purity only slightly....

Two-color ghost interference with photon pairs generated in hot atoms

Directory of Open Access Journals (Sweden)

Dong-Sheng Ding

2012-09-01

Full Text Available We report on an experimental observation of a two-photon ghost interference experiment. A distinguishing feature of our experiment is that the photons are generated via a non-degenerated spontaneous four-wave mixing process in a hot atomic ensemble; therefore the photon has narrow bandwidth. Besides, there is a large difference in frequency between two photons in a pair. Our works may be important to achieve more secure, large transmission capacity long-distance quantum communication.

Optical generation of matter qubit graph states

International Nuclear Information System (INIS)

Benjamin, S C; Eisert, J; Stace, T M

2005-01-01

We present a scheme for rapidly entangling matter qubits in order to create graph states for one-way quantum computing. The qubits can be simple three-level systems in separate cavities. Coupling involves only local fields and a static (unswitched) linear optics network. Fusion of graph-state sections occurs with, in principle, zero probability of damaging the nascent graph state. We avoid the finite thresholds of other schemes by operating on two entangled pairs, so that each generates exactly one photon. We do not require the relatively slow single qubit local flips to be applied during the growth phase: growth of the graph state can then become a purely optical process. The scheme naturally generates graph states with vertices of high degree and so is easily able to construct minimal graph states, with consequent resource savings. The most efficient approach will be to create new graph-state edges even as qubits elsewhere are measured, in a 'just in time' approach. An error analysis indicates that the scheme is relatively robust against imperfections in the apparatus

Two-dimensionally confined topological edge states in photonic crystals

International Nuclear Information System (INIS)

Barik, Sabyasachi; Miyake, Hirokazu; DeGottardi, Wade; Waks, Edo; Hafezi, Mohammad

2016-01-01

We present an all-dielectric photonic crystal structure that supports two-dimensionally confined helical topological edge states. The topological properties of the system are controlled by the crystal parameters. An interface between two regions of differing band topologies gives rise to topological edge states confined in a dielectric slab that propagate around sharp corners without backscattering. Three-dimensional finite-difference time-domain calculations show these edges to be confined in the out-of-plane direction by total internal reflection. Such nanoscale photonic crystal architectures could enable strong interactions between photonic edge states and quantum emitters. (paper)

Supercontinuum Generation in a Photonic Crystal Fibre

Institute of Scientific and Technical Information of China (English)

YAN Pei-Guang; RUAN Shuang-Chen; LIN Hao-Jia; DU Chen-Lin; YU Yong-Qin; LU Ke-Cheng; YAO Jian-Quan

2004-01-01

@@ Nearly 1000-nm broad continuum from 390nm to 1370nm is generated in a 2-m long photonic crystal fibre. The maximum total power of supercontinuum is measured to be 60mW with the pumping power of 800mW output from a 200-fs Ti:sapphire laser. The evolution of the pumping light into supercontinuum is experimentally studied in detail. It is found that the mechanism for supercontinuum generation has direct relations with Raman effect and soliton effect, and the four-wave mixing plays an important role in the last phase of the supercontinuum generation.

Entanglement between electronic states in silicene and photons

Energy Technology Data Exchange (ETDEWEB)

Rastgoo, S. [Physics Department, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Shirkani, H. [Physics Department, Persian Gulf University, Bushehr 75169 (Iran, Islamic Republic of); Golshan, M.M., E-mail: golshan@susc.ac.ir [Physics Department, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

2015-06-12

Temporal behavior of entanglement between electrons in silicene and single mode radiations is reported. We show that the corresponding total Hamiltonian and time evolution operators are block diagonal. Initial states are divided into two categories for which buckling and the intrinsic spin–orbit effects are either of opposite or the same signs. Negativity shows that π-electrons and photons periodically become entangled for both categories. The entanglement spontaneously shows abrupt variations when buckling and the spin–orbit effects are equal but opposite in sign, leading to quantum phase transitions. As photonic excitations increase, the entanglement exhibits plateaus of constant durations for such initial states. - Highlights: • Time evolution of entanglement between π-electrons and photons in silicene is reported. • Intrinsic spin–orbit coupling (ISOC) and buckling effect (BE) are taken into account. • Initial states with ISOC and BE of opposite signs show quantum phase transitions. • Quantum phase transitions spontaneously occur when ISOC is equal to BE. • Periodic plateaus of maximal entanglement are observed for high photonic excitations.

Density of photonic states in cholesteric liquid crystals

Science.gov (United States)

Dolganov, P. V.

2015-04-01

Density of photonic states ρ (ω ) , group vg, and phase vph velocity of light, and the dispersion relation between wave vector k , and frequency ω (k ) were determined in a cholesteric photonic crystal. A highly sensitive method (measurement of rotation of the plane of polarization of light) was used to determine ρ (ω ) in samples of different quality. In high-quality samples a drastic increase in ρ (ω ) near the boundaries of the stop band and oscillations related to Pendellösung beatings are observed. In low-quality samples photonic properties are strongly modified. The maximal value of ρ (ω ) is substantially smaller, and density of photonic states increases near the selective reflection band without oscillations in ρ (ω ) . Peculiarities of ρ (ω ) , vg, and ω (k ) are discussed. Comparison of the experimental results with theory was performed.

Quantum state detection and state preparation based on cavity-enhanced nonlinear interaction of atoms with single photon

Science.gov (United States)

Hosseini, Mahdi

Our ability to engineer quantum states of light and matter has significantly advanced over the past two decades, resulting in the production of both Gaussian and non-Gaussian optical states. The resulting tailored quantum states enable quantum technologies such as quantum optical communication, quantum sensing as well as quantum photonic computation. The strong nonlinear light-atom interaction is the key to deterministic quantum state preparation and quantum photonic processing. One route to enhancing the usually weak nonlinear light-atom interactions is to approach the regime of cavity quantum electrodynamics (cQED) interaction by means of high finesse optical resonators. I present results from the MIT experiment of large conditional cross-phase modulation between a signal photon, stored inside an atomic quantum memory, and a control photon that traverses a high-finesse optical cavity containing the atomic memory. I also present a scheme to probabilistically change the amplitude and phase of a signal photon qubit to, in principle, arbitrary values by postselection on a control photon that has interacted with that state. Notably, small changes of the control photon polarization measurement basis by few degrees can substantially change the amplitude and phase of the signal state. Finally, I present our ongoing effort at Purdue to realize similar peculiar quantum phenomena at the single photon level on chip scale photonic systems.

Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection.

Science.gov (United States)

Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

2015-03-23

Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn "photon-switches" to "OFF" state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished.

Cross-section measurements of final states with photons and jets with the ATLAS experiment

CERN Document Server

Villaplana Perez, Miguel; The ATLAS collaboration

2017-01-01

The production of jets and prompt isolated photons at hadron colliders provides a stringent test of perturbative quantum chromodynamics (pQCD) and can be used to probe the proton structure. The ATLAS collaboration has performed precise measurements of the inclusive production of isolated prompt photons at a centre-of-mass energy of 13 TeV, differential in both rapidity and photon transverse momentum. In addition, the integrated and differential cross sections for isolated photon pairs at 8 TeV have been measured. The results are compared with state-of-the-art theory predictions at NLO in QCD and with predictions of several Monte Carlo (MC) generators. The production of prompt photons in association with jets provides an additional testing ground for pQCD with a hard colourless probe less affected by hadronisation effects than jet production. Jet production can also be used to probe the gluon density function of the proton. Specific topologies can be used to extract the strong coupling constant. The ATLAS coll...

Hybrid entanglement swapping of photons: Creating the orbital angular momentum Bell states and Greenberger-Horne-Zeilinger states

International Nuclear Information System (INIS)

Chen Lixiang; She Weilong

2011-01-01

Twisted photons offer a high-dimensional Hilbert space with the degree of freedom of orbital angular momentum (OAM). Entanglement swapping allows entangling photons that never interact. We report in this paper the hybrid entanglement swapping from multiphoton spin-entangled states to multiphoton OAM entangled states with the aid of N-pair hybrid spin-OAM entangled photons. Our scheme provides a feasible method for creating the two-photon OAM Bell states (N=2) or multiphoton multidimensional OAM Greenberger-Horne-Zeilinger states (N≥3). We highlight the advantage of multiparticle, multidimensional entangled states in some applications of quantum information protocols.

Entanglement, Einstein Podolsky Rosen correlations and Schrodinger cat state generation by quantum-injected optical parametric amplification

International Nuclear Information System (INIS)

De Martini, Francesco; Sciarrino, Fabio

2007-01-01

We investigate the multi-photon quantum superposition state generated by the quantum-injected high-gain optical parametric amplification of a single photon. The physical configurations based on the optimal universal and on the phase-covariant quantum cloning have been adopted. The theoretical results are supported by a set of experiments leading to the generation of an average number of clones in excess of 10 3

Conditional preparation of states containing a definite number of photons

International Nuclear Information System (INIS)

O'Sullivan, Malcolm N.; Chan, Kam Wai Clifford; Boyd, Robert W.; Lakshminarayanan, Vasudevan

2008-01-01

A technique for conditionally creating single-mode or multimode photon-number states is analyzed using Bayesian theory. We consider the heralded N-photon states created from the photons produced by an unseeded optical parametric amplifier when the heralding detector is the time-multiplexed photon-number-resolving detector recently demonstrated by Fitch et al. [Phys. Rev. A 68, 043814 (2003)] and simultaneously by Achilles et al. [Opt. Lett. 28, 2387 (2003)]. We find that even with significant loss in the heralding detector, fields with sub-Poissonian photon-number distributions can be created. We also show that heralded multimode fields created using this technique are more robust against detector loss than are single-mode fields

Generation of narrow-band polarization-entangled photon pairs at a rubidium D1 line

International Nuclear Information System (INIS)

Tian Long; Li Shujing; Yuan Haoxiang; Wang Hai

2016-01-01

Using the process of cavity-enhanced spontaneous parametric down-conversion (SPDC), we generate a narrow-band polarization-entangled photon pair resonant on the rubidium (Rb) D1 line (795 nm). The degenerate single-mode photon pair is selected by multiple temperature controlled etalons. The linewidth of generated polarization-entangled photon pairs is 15 MHz which matches the typical atomic memory bandwidth. The measured Bell parameter for the polarization-entangled photons S = 2.73 ± 0.04 which violates the Bell-CHSH inequality by ∼18 standard deviations. The presented entangled photon pair source could be utilized in quantum communication and quantum computing based on quantum memories in atomic ensemble. (author)

Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

International Nuclear Information System (INIS)

Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

2015-01-01

We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

Triple photonic band-gap structure dynamically induced in the presence of spontaneously generated coherence

International Nuclear Information System (INIS)

Gao Jinwei; Bao Qianqian; Wan Rengang; Cui Cuili; Wu Jinhui

2011-01-01

We study a cold atomic sample coherently driven into the five-level triple-Λ configuration for attaining a dynamically controlled triple photonic band-gap structure. Our numerical calculations show that three photonic band gaps with homogeneous reflectivities up to 92% can be induced on demand around the probe resonance by a standing-wave driving field in the presence of spontaneously generated coherence. All these photonic band gaps are severely malformed with probe reflectivities declining rapidly to very low values when spontaneously generated coherence is gradually weakened. The triple photonic band-gap structure can also be attained in a five-level chain-Λ system of cold atoms in the absence of spontaneously generated coherence, which however requires two additional traveling-wave fields to couple relevant levels.

Time-resolved measurement of the quantum states of photons using two-photon interference with short-time reference pulses

International Nuclear Information System (INIS)

Ren Changliang; Hofmann, Holger F.

2011-01-01

To fully utilize the energy-time degree of freedom of photons for optical quantum-information processes, it is necessary to control and characterize the temporal quantum states of the photons at extremely short time scales. For measurements of the temporal coherence of the quantum states beyond the time resolution of available detectors, two-photon interference with a photon in a short-time reference pulse may be a viable alternative. In this paper, we derive the temporal measurement operators for the bunching statistics of a single-photon input state with a photon from a weak coherent reference pulse. It is shown that the effects of the pulse shape of the reference pulse can be expressed in terms of a spectral filter selecting the bandwidth within which the measurement can be treated as an ideal projection on eigenstates of time. For full quantum tomography, temporal coherence can be determined by using superpositions of reference pulses at two different times. Moreover, energy-time entanglement can be evaluated based on the two-by-two entanglement observed in the coherences between pairs of detection times.

Theoretical Analysis of Spectral Correlations Between Photon Pairs Generated in Nanoscale Silicon Waveguides

International Nuclear Information System (INIS)

Lu Liang-Liang; Xu Ping; Xu Jian-Ning; Zhu Shi-Ning; He Guang-Qiang

2015-01-01

Spontaneous four wave mixing in nonlinear waveguide is one of the excellent technique for generating photon pairs in well-defined guided modes. Here we present a comprehensive study of the frequency characteristic of correlated photon pairs generated in telecom C-band from a dispersion-engineered silicon wire waveguide. We have demonstrated that the waveguide configuration, shape of pump pulse, two-photon absorption as well as linear losses have significant influences on the biphoton spectral characteristics and the amount of frequency entanglement generated. The superior performance as well as the structural compactness and CMOS compatibility makes the silicon wire waveguide an ideal integrated platform for the implementation of on-chip quantum technologies. (paper)

On mixed electron-photon radiation therapy optimization using the column generation approach.

Science.gov (United States)

Renaud, Marc-André; Serban, Monica; Seuntjens, Jan

2017-08-01

Despite considerable increase in the number of degrees of freedom handled by recent radiotherapy optimisation algorithms, treatments are still typically delivered using a single modality. Column generation is an iterative method for solving large optimisation problems. It is well suited for mixed-modality (e.g., photon-electron) optimisation as the aperture shaping and modality selection problem can be solved rapidly, and the performance of the algorithm scales favourably with increasing degrees of freedom. We demonstrate that the column generation method applied to mixed photon-electron planning can efficiently generate treatment plans and investigate its behaviour under different aperture addition schemes. Column generation was applied to the problem of mixed-modality treatment planning for a chest wall case and a leg sarcoma case. 6 MV beamlets (100 cm SAD) were generated for the photon components along with 5 energies for electron beamlets (6, 9, 12, 16 and 20 MeV), simulated as shortened-SAD (80 cm) beams collimated with a photon MLC. For the chest wall case, IMRT-only, modulated electron radiation therapy (MERT)-only, and mixed electron-photon (MBRT) treatment plans were created using the same planning criteria. For the sarcoma case, MBRT and MERT plans were created to study the behaviour of the algorithm under two different sets of planning criteria designed to favour specific modalities. Finally, the efficiency and plan quality of four different aperture addition schemes was analysed by creating chest wall MBRT treatment plans which incorporate more than a single aperture per iteration of the column generation loop based on a heuristic aperture ranking scheme. MBRT plans produced superior target coverage and homogeneity relative to IMRT and MERT plans created using the same optimisation criteria, all the while preserving the normal tissue-sparing advantages of electron therapy. Adjusting the planning criteria to favour a specific modality in the sarcoma

Electro-optic routing of photons from a single quantum dot in photonic integrated circuits

Science.gov (United States)

Midolo, Leonardo; Hansen, Sofie L.; Zhang, Weili; Papon, Camille; Schott, Rüdiger; Ludwig, Arne; Wieck, Andreas D.; Lodahl, Peter; Stobbe, Søren

2017-12-01

Recent breakthroughs in solid-state photonic quantum technologies enable generating and detecting single photons with near-unity efficiency as required for a range of photonic quantum technologies. The lack of methods to simultaneously generate and control photons within the same chip, however, has formed a main obstacle to achieving efficient multi-qubit gates and to harness the advantages of chip-scale quantum photonics. Here we propose and demonstrate an integrated voltage-controlled phase shifter based on the electro-optic effect in suspended photonic waveguides with embedded quantum emitters. The phase control allows building a compact Mach-Zehnder interferometer with two orthogonal arms, taking advantage of the anisotropic electro-optic response in gallium arsenide. Photons emitted by single self-assembled quantum dots can be actively routed into the two outputs of the interferometer. These results, together with the observed sub-microsecond response time, constitute a significant step towards chip-scale single-photon-source de-multiplexing, fiber-loop boson sampling, and linear optical quantum computing.

Processing multiphoton states through operation on a single photon: Methods and applications

International Nuclear Information System (INIS)

Lin Qing; He Bing; Bergou, Janos A.; Ren, Yuhang

2009-01-01

Multiphoton states are widely applied in quantum information technology. By the methods presented in this paper, the structure of a multiphoton state in the form of multiple single-photon qubit products can be mapped to a single-photon qudit, which could also be in a separable product with other photons. This makes possible the manipulation of such multiphoton states by processing single-photon states. The optical realization of unknown qubit discrimination [B. He, J. A. Bergou, and Y.-H. Ren, Phys. Rev. A 76, 032301 (2007)] is simplified with the transformation methods. Another application is the construction of quantum logic gates, where the inverse transformations back to the input state spaces are also necessary. We especially show that the modified setups to implement the transformations can realize the deterministic multicontrol gates (including Toffoli gate) operating directly on the products of single-photon qubits.

Soliton fission and supercontinuum generation in photonic crystal

Indian Academy of Sciences (India)

2015-10-17

Oct 17, 2015 ... We present a practical design of novel photonic crystal fibre (PCF) to investigate the nonlinear propagation of femtosecond pulses for the application of optical coherence tomography (OCT) based on supercontinuum generation (SCG) process. In addition, this paper contains a brief introduction of the ...

Quantum information processing with mesoscopic photonic states

DEFF Research Database (Denmark)

Madsen, Lars Skovgaard

2012-01-01

photon numbers and the states where one of Stokes parameters is highly excited. To describe the polarization of these state we introduce several new polarization measures which take into account the covariance of the polarization and resolve the polarization manifolds. We experimentally demonstrate...

Full characterization of a three-photon Greenberger-Horne-Zeilinger state using quantum state tomography.

Science.gov (United States)

Resch, K J; Walther, P; Zeilinger, A

2005-02-25

We have performed the first experimental tomographic reconstruction of a three-photon polarization state. Quantum state tomography is a powerful tool for fully describing the density matrix of a quantum system. We measured 64 three-photon polarization correlations and used a "maximum-likelihood" reconstruction method to reconstruct the Greenberger-Horne-Zeilinger state. The entanglement class has been characterized using an entanglement witness operator and the maximum predicted values for the Mermin inequality were extracted.

Correlated Photon Emission from Multiatom Rydberg Dark States

DEFF Research Database (Denmark)

Pritchard, J.D.; Adams, C.S.; Mølmer, Klaus

2012-01-01

We consider three-level atoms driven by two resonant light fields in a ladder scheme where the upper level is a highly excited Rydberg state. We show that the dipole-dipole interactions between Rydberg excited atoms prevents the formation of single particle dark states and leads to strongly corre...... correlated photon pairs from atoms separated by distances large compared to the emission wavelength. For a pair of atoms, this enables realization of an efficient photon-pair source with on average one pair every 30 μs....

High-fidelity frequency down-conversion of visible entangled photon pairs with superconducting single-photon detectors

International Nuclear Information System (INIS)

Ikuta, Rikizo; Kato, Hiroshi; Kusaka, Yoshiaki; Yamamoto, Takashi; Imoto, Nobuyuki; Miki, Shigehito; Yamashita, Taro; Terai, Hirotaka; Wang, Zhen; Fujiwara, Mikio; Sasaki, Masahide; Koashi, Masato

2014-01-01

We experimentally demonstrate a high-fidelity visible-to-telecommunicationwavelength conversion of a photon by using a solid-state-based difference frequency generation. In the experiment, one half of a pico-second visible entangled photon pair at 780 nm is converted to a 1522-nm photon. Using superconducting single-photon detectors with low dark count rates and small timing jitters, we observed a fidelity of 0.93±0.04 after the wavelength conversion

Excited-state lifetime measurement of silicon vacancy centers in diamond by single-photon frequency upconversion

Science.gov (United States)

Rong, Youying; Ma, Jianhui; Chen, Lingxiao; Liu, Yan; Siyushev, Petr; Wu, Botao; Pan, Haifeng; Jelezko, Fedor; Wu, E.; Zeng, Heping

2018-05-01

We report a method with high time resolution to measure the excited-state lifetime of silicon vacancy centers in bulk diamond avoiding timing jitter from the single-photon detectors. Frequency upconversion of the fluorescence emitted from silicon vacancy centers was achieved from 738 nm to 436 nm via sum frequency generation with a short pump pulse. The excited-state lifetime can be obtained by measuring the intensity of upconverted light while the pump delay changes. As a probe, a pump laser with pulse duration of 11 ps provided a high temporal resolution of the measurement. The lifetime extracted from the pump–probe curve was 0.755 ns, which was comparable to the timing jitter of the single-photon detectors.

Entangled photon pair generation by spontaneous parametric down-conversion in finite-length one-dimensional photonic crystals

International Nuclear Information System (INIS)

Centini, M.; Sciscione, L.; Sibilia, C.; Bertolotti, M.; Perina, J. Jr.; Scalora, M.; Bloemer, M.J.

2005-01-01

A description of spontaneous parametric down-conversion in finite-length one-dimensional nonlinear photonic crystals is developed using semiclassical and quantum approaches. It is shown that if a suitable averaging is added to the semiclassical model, its results are in very good agreement with the quantum approach. We propose two structures made with GaN/AlN that generate both degenerate and nondegenerate entangled photon pairs. Both structures are designed so as to achieve a high efficiency of the nonlinear process

Photonic quantum information: science and technology.

Science.gov (United States)

Takeuchi, Shigeki

2016-01-01

Recent technological progress in the generation, manipulation and detection of individual single photons has opened a new scientific field of photonic quantum information. This progress includes the realization of single photon switches, photonic quantum circuits with specific functions, and the application of novel photonic states to novel optical metrology beyond the limits of standard optics. In this review article, the recent developments and current status of photonic quantum information technology are overviewed based on the author's past and recent works.

Silicon Photonics Integrated Circuits for 5th Generation mm-Wave Wireless Communications

DEFF Research Database (Denmark)

Rommel, Simon; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

Hybrid photonic-wireless transmission schemes in the mm-wave frequency are promising candidates to enable the multi-gigabit per second data communications required from wireless and mobile networks of the 5th and future generations. Photonic integration may pave the way to practical applicability...

Topologically protected bound states in photonic parity-time-symmetric crystals.

Science.gov (United States)

Weimann, S; Kremer, M; Plotnik, Y; Lumer, Y; Nolte, S; Makris, K G; Segev, M; Rechtsman, M C; Szameit, A

2017-04-01

Parity-time (PT)-symmetric crystals are a class of non-Hermitian systems that allow, for example, the existence of modes with real propagation constants, for self-orthogonality of propagating modes, and for uni-directional invisibility at defects. Photonic PT-symmetric systems that also support topological states could be useful for shaping and routing light waves. However, it is currently debated whether topological interface states can exist at all in PT-symmetric systems. Here, we show theoretically and demonstrate experimentally the existence of such states: states that are localized at the interface between two topologically distinct PT-symmetric photonic lattices. We find analytical closed form solutions of topological PT-symmetric interface states, and observe them through fluorescence microscopy in a passive PT-symmetric dimerized photonic lattice. Our results are relevant towards approaches to localize light on the interface between non-Hermitian crystals.

Photon technology. Laser process technology; Photon technology. Laser process gijutsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

For developing laser process technology by interaction between substance and photon, the present state, system, R and D issues and proposal of such technology were summarized. Development of the photon technology aims at the modification of bonding conditions of substances by quantum energy of photon, and the new process technology for generating ultra- high temperature and pressure fields by concentrating photon on a minute region. Photon technology contributes to not only the conventional mechanical and thermal forming and removal machining but also function added machining (photon machining) in quantum level and new machining technology ranging from macro- to micro-machining, creating a new industrial field. This technology extends various fields from the basis of physics and chemistry to new bonding technology. Development of a compact high-quality high-power high-efficiency photon source, and advanced photon transmission technology are necessary. The basic explication of an unsolved physicochemical phenomenon related to photon and substance, and development of related application technologies are essential. 328 refs., 147 figs., 13 tabs.

Generalized quantum interference of correlated photon pairs

Science.gov (United States)

Kim, Heonoh; Lee, Sang Min; Moon, Han Seb

2015-01-01

Superposition and indistinguishablility between probability amplitudes have played an essential role in observing quantum interference effects of correlated photons. The Hong-Ou-Mandel interference and interferences of the path-entangled photon number state are of special interest in the field of quantum information technologies. However, a fully generalized two-photon quantum interferometric scheme accounting for the Hong-Ou-Mandel scheme and path-entangled photon number states has not yet been proposed. Here we report the experimental demonstrations of the generalized two-photon interferometry with both the interferometric properties of the Hong-Ou-Mandel effect and the fully unfolded version of the path-entangled photon number state using photon-pair sources, which are independently generated by spontaneous parametric down-conversion. Our experimental scheme explains two-photon interference fringes revealing single- and two-photon coherence properties in a single interferometer setup. Using the proposed interferometric measurement, it is possible to directly estimate the joint spectral intensity of a photon pair source. PMID:25951143

Twin photonic nanojets generated from coherent illumination of microscale sphere and cylinder

Science.gov (United States)

Poteet, Austen; Zhang, Xu A.; Nagai, Hironori; Chang, Chih-Hao

2018-02-01

Photonic nanojets, highly focused beams of light created by planar illumination of a microsphere, have been shown to produce narrow subwavelength beams over distances of several wavelengths in the near field. In this work, we investigate the generation of twin photonic nanojets through the illumination of a microsphere or cylinder from two coherent sources with relative phase shift. Under these conditions, symmetric twin nanojets separated by an intensity null can be generated. Compared to a photonic nanojet, the twin nanojets can achieve an even smaller subwavelength beam, and have the added advantage of having more complex intensity profiles that can be controlled by multiple parameters. Using both finite-difference time-domain and Mie theory models, the width, length, and intensity enhancement factor of the nanojet geometry are found to be functions of the phase, angle offsets, and particle geometry. Such twin photonic nanojets can find applications in optical trapping, manipulation, nanolithography, and enhancement of nonlinear optical properties.

Theory of two-photon interactions with broadband down-converted light and entangled photons

International Nuclear Information System (INIS)

Dayan, Barak

2007-01-01

When two-photon interactions are induced by down-converted light with a bandwidth that exceeds the pump bandwidth, they can obtain a behavior that is pulselike temporally, yet spectrally narrow. At low photon fluxes this behavior reflects the time and energy entanglement between the down-converted photons. However, two-photon interactions such as two-photon absorption (TPA) and sum-frequency generation (SFG) can exhibit such a behavior even at high power levels, as long as the final state (i.e., the atomic level in TPA, or the generated light in SFG) is narrow-band enough. This behavior does not depend on the squeezing properties of the light, is insensitive to linear losses, and has potential applications. In this paper we describe analytically this behavior for traveling-wave down conversion with continuous or pulsed pumping, both for high- and low-power regimes. For this we derive a quantum-mechanical expression for the down-converted amplitude generated by an arbitrary pump, and formulate operators that represent various two-photon interactions induced by broadband light. This model is in excellent agreement with experimental results of TPA and SFG with high-power down-converted light and with entangled photons [Dayan et al., Phys. Rev. Lett. 93, 023005 (2004); 94, 043602 (2005); Pe'er et al., ibid. 94, 073601 (2005)

Novel ultra-wideband photonic signal generation and transmission featuring digital signal processing bit error rate measurements

DEFF Research Database (Denmark)

Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

2009-01-01

We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal.......We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal....

Generation of polarization-entangled photon pairs in a cascade of two type-I crystals pumped by femtosecond pulses

International Nuclear Information System (INIS)

Nambu, Yoshihiro; Usami, Koji; Tsuda, Yoshiyuki; Matsumoto, Keiji; Nakamura, Kazuo

2002-01-01

We report the generation of polarization-entangled photons by femtosecond-pulse-pumped spontaneous parametric down-conversion in a cascade of two type-I crystals. Highly entangled pulsed states were obtained by introducing a temporal delay between the two orthogonal polarization components of the pump field. They exhibited high-visibility quantum interference and a large concurrence value, without the need of postselection using narrow-bandwidth spectral filters. The results are well explained by the theory which incorporates the space-time dependence of interfering two-photon amplitudes if dispersion and birefringence in the crystals are appropriately taken into account. Such a pulsed entangled photon well localized in time domain is useful for various quantum communication experiments, such as quantum cryptography and quantum teleportation

An all-silicon laser by coupling between electronic localized states and defect states of photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Huang Weiqi, E-mail: WQHuang2001@yahoo.com [Institute of Nanophotonic Physics, Key Laboratory of Photoelectron Technology and Application, Guizhou University, Guiyang 550025 (China); Huang Zhongmei; Miao Xinjiang; Cai Chenlan; Liu Jiaxin; Lue Quan [Institute of Nanophotonic Physics, Key Laboratory of Photoelectron Technology and Application, Guizhou University, Guiyang 550025 (China); Liu Shirong, E-mail: Shirong@yahoo.com [State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550003 (China); Qin Chaojian [State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550003 (China)

2012-01-15

In a nano-laser of Si quantum dots (QD), the smaller QD fabricated by nanosecond pulse laser can form the pumping level tuned by the quantum confinement (QC) effect. Coupling between the active centers formed by localized states of surface bonds and the two-dimensional (2D) photonic crystal is used to select model in the nano-laser. The experimental demonstration is reported in which the peaks of stimulated emission at about 600 nm and 700 nm were observed on the Si QD prepared in oxygen after annealing which improves the stimulated emission. It is interesting to make a comparison between the localized electronic states in gap due to defect formed by surface bonds and the localized photonic states in gap of photonic band due to defect of 2D photonic crystal.

System Wide Implementation of Photonically Generated Impulse Radio Ultra-Wideband for Gigabit Fiber-Wireless Access

DEFF Research Database (Denmark)

Yu, Xianbin; Gibbon, Timothy Braidwood; Rodes Lopez, Roberto

2013-01-01

In this paper, we comprehensively review our research work on system wide implementation of photonically generated IR-UWB signals based on relaxation oscillations of a semiconductor laser. Firstly, we present our novel approach as a flexible method for photonic generation of high speed impulse ra...

Experimental investigation of the generation of harmonic photons from the interaction of free electrons with intense laser radiation

International Nuclear Information System (INIS)

Englert, T.J.

1983-01-01

An experimental investigation of the generation of second harmonic photons through the interaction of free electrons with an intense laser beam has been performed. Second harmonic photons with a wavelength of 530nm generated from the interaction of free electrons with 1060nm photons from a neodymium-glass laser are implied by observing Doppler shifted photons with wavelengths of 490nm and 507nm. The observed photon wavelengths results from a Doppler shift of the laser photon wavelengths as viewed in the rest frame of the electrons combined with a Doppler shift of the second harmonic photons emitted from 1600eV and 500eV electrons. Comparison of experimental results with those predicted by cross sections, derived using classical and quantum electrodynamics, shows reasonable agreement with both theories. Although second harmonic photons are created, the dynamics of second harmonic photon generation (accelerated electron motion due to the electromagnetic field or actual two-photon interaction with the electron) cannot be resolved without further experiment

All-solid-state deep ultraviolet laser for single-photon ionization mass spectrometry.

Science.gov (United States)

Yuan, Chengqian; Liu, Xianhu; Zeng, Chenghui; Zhang, Hanyu; Jia, Meiye; Wu, Yishi; Luo, Zhixun; Fu, Hongbing; Yao, Jiannian

2016-02-01

We report here the development of a reflectron time-of-flight mass spectrometer utilizing single-photon ionization based on an all-solid-state deep ultraviolet (DUV) laser system. The DUV laser was achieved from the second harmonic generation using a novel nonlinear optical crystal KBe2BO3F2 under the condition of high-purity N2 purging. The unique property of this laser system (177.3-nm wavelength, 15.5-ps pulse duration, and small pulse energy at ∼15 μJ) bears a transient low power density but a high single-photon energy up to 7 eV, allowing for ionization of chemicals, especially organic compounds free of fragmentation. Taking this advantage, we have designed both pulsed nanospray and thermal evaporation sources to form supersonic expansion molecular beams for DUV single-photon ionization mass spectrometry (DUV-SPI-MS). Several aromatic amine compounds have been tested revealing the fragmentation-free performance of the DUV-SPI-MS instrument, enabling applications to identify chemicals from an unknown mixture.

Quantum State Transfer from a Single Photon to a Distant Quantum-Dot Electron Spin

Science.gov (United States)

He, Yu; He, Yu-Ming; Wei, Yu-Jia; Jiang, Xiao; Chen, Kai; Lu, Chao-Yang; Pan, Jian-Wei; Schneider, Christian; Kamp, Martin; Höfling, Sven

2017-08-01

Quantum state transfer from flying photons to stationary matter qubits is an important element in the realization of quantum networks. Self-assembled semiconductor quantum dots provide a promising solid-state platform hosting both single photon and spin, with an inherent light-matter interface. Here, we develop a method to coherently and actively control the single-photon frequency bins in superposition using electro-optic modulators, and measure the spin-photon entanglement with a fidelity of 0.796 ±0.020 . Further, by Greenberger-Horne-Zeilinger-type state projection on the frequency, path, and polarization degrees of freedom of a single photon, we demonstrate quantum state transfer from a single photon to a single electron spin confined in an InGaAs quantum dot, separated by 5 m. The quantum state mapping from the photon's polarization to the electron's spin is demonstrated along three different axes on the Bloch sphere, with an average fidelity of 78.5%.

Two-photon decay of K-shell vacancy states in heavy atoms

International Nuclear Information System (INIS)

Ilakovac, K.; Uroic, M.; Majer, M.; Pasic, S.; Vukovic, B.

2006-01-01

Two-photon decay has been extensively studied in atomic, nuclear and particle physics since the 1930s when the problem of stability of the 2s state of the hydrogen atom emerged. Since then, many theoretical and experimental investigations have been made on hydrogen and one-electron (H-like) ions and on helium and two-electron (He-like) ions. The work on two-photon decay in many-electron systems involving inner shells started about 30 years ago and, in the meantime, two-photon decay of the K-shell vacancy state has been the subject of many theoretical and experimental studies. Experimental results have been obtained for 2s->1s and higher-state electron ->1s two-photon transitions in molybdenum, and for 2s -> 1s, 3s -> 1s, 3d -> 1s and 4sd -> 1s two-photon transitions in silver, xenon, hafnium and mercury. Nonrelativistic and relativistic calculations of the processes have been made. The relativistic calculations for transitions in molybdenum, silver and xenon atoms are in a reasonable agreement with the experimental results, but some problems remain to be solved. A review of investigations of two-photon transitions in atomic systems is presented

Cross-section measurements of final states with photons and jets with the ATLAS experiment

Science.gov (United States)

Pérez, Miguel Villaplana

2018-01-01

The ATLAS Collaboration has performed precise measurements of the cross-section of final states with photons and/or jets at centre-of-mass energies of 8 and 13 TeV. The results are compared with state-of-the-art theory predictions and with predictions of several Monte Carlo generators. We also present new measurements of transverse energy-energy correlations and their associated asymmetries in multi-jet events at 8 TeV. Both measurements are used to extract the strong coupling constant and test the renormalization group equations.

Applications of a controlled phase gate for photons

International Nuclear Information System (INIS)

Schmid, C.; Kiesel, N.; Weber, U.; Weinfurter, H.; Toth, G; Ursin, R.; Guehne, O.

2005-01-01

Full text: We report on experimental applications of a probabilistic quantum controlled-phase gate for photons. The gate is operating on the polarization degree of freedom and applies a pi phase shift to a target photon, conditioned on the polarization of a control photon. This is experimentally realized by overlapping the input photons on a beam splitter with polarization dependent splitting ratio (TH=1, TV=1/3). The phase is thereby introduced by a second order interference in case two vertically polarized photons are passing the gate. In order to ensure polarization independent weighting coefficients for the output states of all possible input combinations, two beam splitters with reversed splitting ratio (TH=1/3, TV=1) are placed after each output of the overlap BS. The gate allows the implementation of a full Bell state analysis and by this the accomplishment of a complete teleportation experiment. As input we used horizontal, vertical, +45 o , and right circular polarized photon states from which we could deduce a teleportation process tomography for each of the four Bell states detected. Whereas in the Bell state analysis the gate maps an entangled state onto a product state, it can be used as well in the opposite way for an entangling operation. We exploit this fact to generate a certain four qubit entangled state, the so-called four-photon cluster state. In order to do so we apply the gate on two photons of two different EPR pairs originating from a spontaneous parametric down conversion process. The resulting experimental state shows a fidelity of 74.4 ± 1.2 % to the theoretically expected one. By the experimental violation of a specially tailored Bell inequality we are able to proof its non-locality and delimit it from a GHZ state. We demonstrate its genuine four-photon entanglement by a witness measurement. Furthermore we characterize the generated state by the study of its remarkable entanglement persistency properties with respect to the measurement

Exploring photonic topological insulator states in a circuit-QED lattice

Science.gov (United States)

Li, Jing-Ling; Shan, Chuan-Jia; Zhao, Feng

2018-04-01

We propose a simple protocol to explore the topological properties of photonic integer quantum Hall states in a one-dimensional circiut-QED lattice. By periodically modulating the on-site photonic energies in such a lattice, we demonstrate that this one-dimensional lattice model can be mapped into a two-dimensional integer quantum Hall insulator model. Based on the lattice-based cavity input-output theory, we show that both the photonic topological protected edge states and topological invariants can be clearly measured from the final steady state of the resonator lattice after taking into account cavity dissipation. Interestingly, we also find that the measurement signals associated with the above topological features are quite unambitious even in five coupled dissipative resonators. Our work opens up a new prospect of exploring topological states with a small-size dissipative quantum artificial lattice, which is quite attractive to the current quantum optics community.

Surface states in photonic crystals

Directory of Open Access Journals (Sweden)

Vojtíšek P.

2013-05-01

Full Text Available Among many unusual and interesting physical properties of photonic crystals (PhC, in recent years, the propagation of surface electromagnetic waves along dielectric PhC boundaries have attracted considerable attention, also in connection to their possible applications. Such surfaces states, produced with the help of specialized defects on PhC boundaries, similarly to surfaces plasmons, are localized surfaces waves and, as such, can be used in various sensing applications. In this contribution, we present our recent studies on numerical modelling of surface states (SS for all three cases of PhC dimensionality. Simulations of these states were carried out by the use of plane wave expansion (PWE method via the MIT MPB package.

Highly selective population of two excited states in nonresonant two-photon absorption

International Nuclear Information System (INIS)

Zhang Hui; Zhang Shi-An; Sun Zhen-Rong

2011-01-01

A nonresonant two-photon absorption process can be manipulated by tailoring the ultra-short laser pulse. In this paper, we theoretically demonstrate a highly selective population of two excited states in the nonresonant two-photon absorption process by rationally designing a spectral phase distribution. Our results show that one excited state is maximally populated while the other state population is widely tunable from zero to the maximum value. We believe that the theoretical results may play an important role in the selective population of a more complex nonlinear process comprising nonresonant two-photon absorption, such as resonance-mediated (2+1)-three-photon absorption and (2+1)-resonant multiphoton ionization. (atomic and molecular physics)

Probabilistically cloning two single-photon states using weak cross-Kerr nonlinearities

International Nuclear Information System (INIS)

Zhang, Wen; Rui, Pinshu; Zhang, Ziyun; Yang, Qun

2014-01-01

By using quantum nondemolition detectors (QNDs) based on weak cross-Kerr nonlinearities, we propose an experimental scheme for achieving 1→2 probabilistic quantum cloning (PQC) of a single-photon state, secretly choosing from a two-state set. In our scheme, after a QND is performed on the to-be-cloned photon and the assistant photon, a single-photon projection measurement is performed by a polarization beam splitter (PBS) and two single-photon trigger detectors (SPTDs). The measurement is to judge whether the PQC should be continued. If the cloning fails, a cutoff is carried out and some operations are omitted. This makes our scheme economical. If the PQC is continued according to the measurement result, two more QNDs and some unitary operations are performed on the to-be-cloned photon and the cloning photon to achieve the PQC in a nearly deterministic way. Our experimental scheme for PQC is feasible for future technology. Furthermore, the quantum logic network of our PQC scheme is presented. In comparison with similar networks, our PQC network is simpler and more economical. (paper)

Supercontinuum Generation in Uniform and Tapered Photonic Crystal Fibers

DEFF Research Database (Denmark)

Sørensen, Simon Toft; Møller, Uffe Visbech; Larsen, Casper

Supercontinuum generation (SCG) is a striking phenomenon of extreme spectral broadening involving a wealth of beautiful nonlinear physics. The study of SCG and development of today’s commercial sources really took off with the invention of the photonic crystal fiber (PCF), in which light can be m...

Initial steps of supercontinuum generation in photonic crystal fibers

DEFF Research Database (Denmark)

Hilligsøe, Karen Marie; Paulsen, H.N.; Thøgersen, J.

2003-01-01

The onset of supercontinuum generation in a photonic crystal fiber is investigated experimentally and numerically as a function of pump wavelength and intensity with 100-fs pulses. Soliton formation is found to be the determining factor in the initial step. The formation and behavior of a blueshi...

Next-Generation Photon Sources for Grand Challenges in Science and Energy

Energy Technology Data Exchange (ETDEWEB)

None

2009-05-01

to avoid radiation damage in high-resolution spatial imaging and to avoid space-charge broadening in photoelectron spectroscopy and microscopy. But light sources alone are not enough. The photons produced by next-generation light sources must be measured by state-of-the-art experiments installed at fully equipped end stations. Sophisticated detectors with unprecedented spatial, temporal, and spectral resolution must be designed and created. The theory of ultrafast phenomena that have never before been observed must be developed and implemented. Enormous data sets of diffracted signals in reciprocal space and across wide energy ranges must be collected and analyzed in real time so that they can guide the ongoing experiments. These experimental challenges - end stations, detectors, sophisticated experiments, theory, and data handling - must be planned and provided for as part of the photon source.

Single-photon manipulation in Nanophotonic Circuits

DEFF Research Database (Denmark)

Hansen, Sofie Lindskov

Quantum dots in photonic nanostructures has long been known to be a very powerful and versatile solid-state platform for conducting quantum optics experiments. The present PhD thesis describes experimental demonstrations of single-photon generation and subsequent manipulation all realized...... on a gallium arsenide platform. This platform offers near-unity coupling between embedded single-photon emitters and a photonic mode, as well as the ability to suppress decoherence mechanisms, making it highly suited for quantum information applications. In this thesis we show how a single-photon router can...... be realized on a chip with embedded quantum dots. This allows for on-chip generation and manipulation of single photons. The router consists of an on-chip interferometer where the phase difference between the arms of the interferometer is controlled electrically. The response time of the device...

Energy-Tunable Sources of Entangled Photons: A Viable Concept for Solid-State-Based Quantum Relays

Science.gov (United States)

Trotta, Rinaldo; Martín-Sánchez, Javier; Daruka, Istvan; Ortix, Carmine; Rastelli, Armando

2015-04-01

We propose a new method of generating triggered entangled photon pairs with wavelength on demand. The method uses a microstructured semiconductor-piezoelectric device capable of dynamically reshaping the electronic properties of self-assembled quantum dots (QDs) via anisotropic strain engineering. Theoretical models based on k .p theory in combination with finite-element calculations show that the energy of the polarization-entangled photons emitted by QDs can be tuned in a range larger than 100 meV without affecting the degree of entanglement of the quantum source. These results pave the way towards the deterministic implementation of QD entanglement resources in all-electrically-controlled solid-state-based quantum relays.

Dynamics of Spontaneous Emission Controlled by Local Density of States in Photonic Crystals

DEFF Research Database (Denmark)

Lodahl, Peter; Nikolaev, Ivan S.; van Driel, A. Floris

2006-01-01

We have measured time-resolved spontaneous emission from quantum dots in 3D photonic crystals. Due to the spatially dependent local density of states, the distribution of decay rates varies strongly with the photonic crystal lattice parameter.......We have measured time-resolved spontaneous emission from quantum dots in 3D photonic crystals. Due to the spatially dependent local density of states, the distribution of decay rates varies strongly with the photonic crystal lattice parameter....

Microwave-Controlled Generation of Shaped Single Photons in Circuit Quantum Electrodynamics

Directory of Open Access Journals (Sweden)

M. Pechal

2014-10-01

Full Text Available Large-scale quantum information processors or quantum communication networks will require reliable exchange of information between spatially separated nodes. The links connecting these nodes can be established using traveling photons that need to be absorbed at the receiving node with high efficiency. This is achievable by shaping the temporal profile of the photons and absorbing them at the receiver by time reversing the emission process. Here, we demonstrate a scheme for creating shaped microwave photons using a superconducting transmon-type three-level system coupled to a transmission line resonator. In a second-order process induced by a modulated microwave drive, we controllably transfer a single excitation from the third level of the transmon to the resonator and shape the emitted photon. We reconstruct the density matrices of the created single-photon states and show that the photons are antibunched. We also create multipeaked photons with a controlled amplitude and phase. In contrast to similar existing schemes, the one we present here is based solely on microwave drives, enabling operation with fixed frequency transmons.

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits.

Science.gov (United States)

Yu, Leo; Natarajan, Chandra M; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S; Tanner, Michael G; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H; Fejer, Martin M; Yamamoto, Yoshihisa

2015-11-24

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

Recommendations and illustrations for the evaluation of photonic random number generators

Science.gov (United States)

Hart, Joseph D.; Terashima, Yuta; Uchida, Atsushi; Baumgartner, Gerald B.; Murphy, Thomas E.; Roy, Rajarshi

2017-09-01

The never-ending quest to improve the security of digital information combined with recent improvements in hardware technology has caused the field of random number generation to undergo a fundamental shift from relying solely on pseudo-random algorithms to employing optical entropy sources. Despite these significant advances on the hardware side, commonly used statistical measures and evaluation practices remain ill-suited to understand or quantify the optical entropy that underlies physical random number generation. We review the state of the art in the evaluation of optical random number generation and recommend a new paradigm: quantifying entropy generation and understanding the physical limits of the optical sources of randomness. In order to do this, we advocate for the separation of the physical entropy source from deterministic post-processing in the evaluation of random number generators and for the explicit consideration of the impact of the measurement and digitization process on the rate of entropy production. We present the Cohen-Procaccia estimate of the entropy rate h (𝜖 ,τ ) as one way to do this. In order to provide an illustration of our recommendations, we apply the Cohen-Procaccia estimate as well as the entropy estimates from the new NIST draft standards for physical random number generators to evaluate and compare three common optical entropy sources: single photon time-of-arrival detection, chaotic lasers, and amplified spontaneous emission.

Recommendations and illustrations for the evaluation of photonic random number generators

Directory of Open Access Journals (Sweden)

Joseph D. Hart

2017-09-01

Full Text Available The never-ending quest to improve the security of digital information combined with recent improvements in hardware technology has caused the field of random number generation to undergo a fundamental shift from relying solely on pseudo-random algorithms to employing optical entropy sources. Despite these significant advances on the hardware side, commonly used statistical measures and evaluation practices remain ill-suited to understand or quantify the optical entropy that underlies physical random number generation. We review the state of the art in the evaluation of optical random number generation and recommend a new paradigm: quantifying entropy generation and understanding the physical limits of the optical sources of randomness. In order to do this, we advocate for the separation of the physical entropy source from deterministic post-processing in the evaluation of random number generators and for the explicit consideration of the impact of the measurement and digitization process on the rate of entropy production. We present the Cohen-Procaccia estimate of the entropy rate h(,τ as one way to do this. In order to provide an illustration of our recommendations, we apply the Cohen-Procaccia estimate as well as the entropy estimates from the new NIST draft standards for physical random number generators to evaluate and compare three common optical entropy sources: single photon time-of-arrival detection, chaotic lasers, and amplified spontaneous emission.

Effects of four-wave mixing on four-photon resonance excitation and ionization in the presence of a three-photon intermediate state resonance enhancement

International Nuclear Information System (INIS)

Payne, M.G.; Miller, J.C.; Hart, R.C.; Garrett, W.R.

1991-01-01

We consider effects which occur when four-wave sum frequency generation and multiphoton ionization are induced by lasers tuned near a three-photon resonance and simultaneously near or at a dipole allowed four-photon resonance. In studies with unfocused laser beams, if the phase mismatch of the generated four-wave-mixing field is large and the related two-photon resonance for the absorption of a four-wave-mixing photon and a laser photon results in strong absorption of the four-wave-mixing field, a coherent cancellation occurs between the pumping of the resonance by two- and four-photon processes. This interference effect occurs when the first laser is tuned on either side of the three-photon resonance and |Δk rL |much-gt 1, where Δk r is the mismatch and L is the length of the path of the laser beams in the gas. With focused laser beams large differences occur between ionization with unidirectional beams and with counterpropagating laser beams when |Δk rb |much-gt 1, where b is the confocal parameter of the focused laser beams. Strong absorption of the four-wave-mixing field is shown not to be necessary for strong destructive interference with focused laser beams when the phase mismatch is large. This work also suggests an explanation for earlier experiments where the presence of a four-photon resonance enabled the generation of third-harmonic light in a positively dispersive wavelength region. We argue that this process can occur when the laser used to achieve the four-photon resonance is focused on the small z (z is the coordinate in the direction of propagation) side of the focal point of the laser responsible for the third-harmonic generation

Chiral current generation in QED by longitudinal photons

Energy Technology Data Exchange (ETDEWEB)

Acosta Avalo, J.L., E-mail: jlacosta@instec.cu [Instituto Superior de Tecnologías y Ciencias Aplicadas (INSTEC), Ave Salvador Allende, No. 1110, Vedado, La Habana 10400 (Cuba); Pérez Rojas, H., E-mail: hugo@icimaf.cu [Instituto de Cibernética, Matemática y Física (ICIMAF), Calle E esq 15, No. 309, Vedado, La Habana 10400 (Cuba)

2016-08-15

We report the generation of a pseudovector electric current having imbalanced chirality in an electron–positron strongly magnetized gas in QED. It propagates along the external applied magnetic field B as a chiral magnetic effect in QED. It is triggered by a perturbative electric field parallel to B, associated to a pseudovector longitudinal mode propagating along B. An electromagnetic chemical potential was introduced, but our results remain valid even when it vanishes. A nonzero fermion mass was assumed, which is usually considered vanishing in the literature. In the quantum field theory formalism at finite temperature and density, an anomaly relation for the axial current was found for a medium of massive fermions. It bears some analogy to the Adler–Bell–Jackiw anomaly. From the expression for the chiral current in terms of the photon self-energy tensor in a medium, it is obtained that electrons and positrons scattered by longitudinal photons (inside the light cone) contribute to the chiral current, as well as the to pair creation due to longitudinal photons (out of light cone). In the static limit, an electric pseudovector current is obtained in the lowest Landau level.

Chiral current generation in QED by longitudinal photons

Directory of Open Access Journals (Sweden)

J.L. Acosta Avalo

2016-08-01

Full Text Available We report the generation of a pseudovector electric current having imbalanced chirality in an electron–positron strongly magnetized gas in QED. It propagates along the external applied magnetic field B as a chiral magnetic effect in QED. It is triggered by a perturbative electric field parallel to B, associated to a pseudovector longitudinal mode propagating along B. An electromagnetic chemical potential was introduced, but our results remain valid even when it vanishes. A nonzero fermion mass was assumed, which is usually considered vanishing in the literature. In the quantum field theory formalism at finite temperature and density, an anomaly relation for the axial current was found for a medium of massive fermions. It bears some analogy to the Adler–Bell–Jackiw anomaly. From the expression for the chiral current in terms of the photon self-energy tensor in a medium, it is obtained that electrons and positrons scattered by longitudinal photons (inside the light cone contribute to the chiral current, as well as the to pair creation due to longitudinal photons (out of light cone. In the static limit, an electric pseudovector current is obtained in the lowest Landau level.

A homodyne detector integrated onto a photonic chip for measuring quantum states and generating random numbers

Science.gov (United States)

Raffaelli, Francesco; Ferranti, Giacomo; Mahler, Dylan H.; Sibson, Philip; Kennard, Jake E.; Santamato, Alberto; Sinclair, Gary; Bonneau, Damien; Thompson, Mark G.; Matthews, Jonathan C. F.

2018-04-01

Optical homodyne detection has found use as a characterisation tool in a range of quantum technologies. So far implementations have been limited to bulk optics. Here we present the optical integration of a homodyne detector onto a silicon photonics chip. The resulting device operates at high speed, up 150 MHz, it is compact and it operates with low noise, quantified with 11 dB clearance between shot noise and electronic noise. We perform on-chip quantum tomography of coherent states with the detector and show that it meets the requirements for characterising more general quantum states of light. We also show that the detector is able to produce quantum random numbers at a rate of 1.2 Gbps, by measuring the vacuum state of the electromagnetic field and applying off-line post processing. The produced random numbers pass all the statistical tests provided by the NIST test suite.

Electrically tunable robust edge states in graphene-based topological photonic crystal slabs

Science.gov (United States)

Song, Zidong; Liu, HongJun; Huang, Nan; Wang, ZhaoLu

2018-03-01

Topological photonic crystals are optical structures supporting topologically protected unidirectional edge states that exhibit robustness against defects. Here, we propose a graphene-based all-dielectric photonic crystal slab structure that supports two-dimensionally confined topological edge states. These topological edge states can be confined in the out-of-plane direction by two parallel graphene sheets. In the structure, the excitation frequency range of topological edge states can be dynamically and continuously tuned by varying bias voltage across the two parallel graphene sheets. Utilizing this kind of architecture, we construct Z-shaped channels to realize topological edge transmission with diffrerent frequencies. The proposal provides a new degree of freedom to dynamically control topological edge states and potential applications for robust integrated photonic devices and optical communication systems.

Production of four-prong final states in photon-photon collisions

International Nuclear Information System (INIS)

Buijs, A.

1987-01-01

This thesis describes the measurement, analysis and discussion of the reaction γγ → X, where X is a hadronic final state with four charged particles. In particular, we have investigated the states 2π + 2π - , K ± π -+ π + π - , K + K - π + π - , 2K + 2K - and panti pπ + π - . The experiment was performed with the TPC/Two-Gamma facility at the e + e - collider PEP at the Standford Linear Accelerator Center. The process γγ → 2π + 2π - had been measured in the beginning of this decade. The shape of the measured cross section suggested the presence of a resonance in this channel, and many such interpretations were brought forth in the following years. In ch. 2, these interpretations and theories are reviewed and a motivation is given for the investigation of states similar to 2π + 2π - , but containing kaons and protons. Also, the existing data from related experiments in radiative J/ψ decays and hadronic collisions are listed. In the last section of the chapter, the outstanding features of the TPC/Two-Gamma detector for the measurement of four-prong events are emphasized. Ch. 3 is a very brief overview of the kinematical properties of the two-photon initial state, which is brought about by the exchange of two photons by the colliding electron and positron. In ch. 4 the details of the detector system are given, and the method used to measure and analyze events from exclusive four-particle final states is outlined. The results of the measurements are given in ch. 5. Ch. 6 concludes with a discussion of the results, and an interpretation of the measurements. 89 refs.; 68 figs.; 12 tabs

Analysis of deterministic swapping of photonic and atomic states through single-photon Raman interaction

Science.gov (United States)

Rosenblum, Serge; Borne, Adrien; Dayan, Barak

2017-03-01

The long-standing goal of deterministic quantum interactions between single photons and single atoms was recently realized in various experiments. Among these, an appealing demonstration relied on single-photon Raman interaction (SPRINT) in a three-level atom coupled to a single-mode waveguide. In essence, the interference-based process of SPRINT deterministically swaps the qubits encoded in a single photon and a single atom, without the need for additional control pulses. It can also be harnessed to construct passive entangling quantum gates, and can therefore form the basis for scalable quantum networks in which communication between the nodes is carried out only by single-photon pulses. Here we present an analytical and numerical study of SPRINT, characterizing its limitations and defining parameters for its optimal operation. Specifically, we study the effect of losses, imperfect polarization, and the presence of multiple excited states. In all cases we discuss strategies for restoring the operation of SPRINT.

Enhanced two-photon emission from a dressed biexciton

International Nuclear Information System (INIS)

Sánchez Muñoz, Carlos; Laussy, Fabrice P; Tejedor, Carlos; Valle, Elena del

2015-01-01

Radiative two-photon cascades from biexcitons in semiconductor quantum dots under resonant two-photon excitation are promising candidates for the generation of photon pairs. In this work, we propose a scheme to obtain two-photon emission that allows us to operate under very intense driving fields. This approach relies on the Purcell enhancement of two-photon virtual transitions between states of the biexciton dressed by the laser. The richness provided by the biexcitonic level structure allows to reach a variety of regimes, from antibunched and bunched photon pairs with polarization orthogonal to the driving field, to polarization entangled two-photon emission. This provides evidence that the general paradigm of two-photon emission from a ladder of dressed states can find interesting, particular implementations in a variety of systems. (paper)

Efficient Entanglement Concentration of Nonlocal Two-Photon Polarization-Time-Bin Hyperentangled States

Science.gov (United States)

Wang, Zi-Hang; Yu, Wen-Xuan; Wu, Xiao-Yuan; Gao, Cheng-Yan; Alzahrani, Faris; Hobiny, Aatef; Deng, Fu-Guo

2018-03-01

We present two different hyperentanglement concentration protocols (hyper-ECPs) for two-photon systems in nonlocal polarization-time-bin hyperentangled states with known parameters, including Bell-like and cluster-like states, resorting to the parameter splitting method. They require only one of two parties in quantum communication to operate her photon in the process of entanglement concentration, not two, and they have the maximal success probability. They work with linear optical elements and have good feasibility in experiment, especially in the case that there are a big number of quantum data exchanged as the parties can obtain the information about the parameters of the nonlocal hyperentangled states by sampling a subset of nonlocal hyperentangled two-photon systems and measuring them. As the quantum state of photons in the time-bin degree of freedom suffers from less noise in an optical-fiber channel, these hyper-ECPs may have good applications in practical long-distance quantum communication in the future.

Search for SUSY in final states with photons at CMS

Directory of Open Access Journals (Sweden)

Ntomari Eleni

2013-05-01

Full Text Available Résumé The Compact Muon Solenoid (CMS collaboration has developed a complete program of searches beyond the Standard Model (SM covering a wide range of final states. This document focuses on searches in final states with photons and missing transverse energy ETmiss organised in three analyses. The first two include comparison of the ETmiss distribution (isolation sideband method in events with either at least two photons plus at least one hadronic jet, or at least one photon plus at least two hadronic jets. The third analysis corresponds to a new approach, the Jet-Gamma Balance (JGB method, for events with at least one photon plus at least three hadronic jets.We observe no significant deviations from the SM expectation and thus derive upper limits on the signal cross section at the 95% confidence level (CL for a range of squark, gluino and neutralino mass points in the Gauge Mediated Supersymmetry Breaking scenario.

Enhanced linear photonic nanojet generated by core-shell optical microfibers

Science.gov (United States)

Liu, Cheng-Yang; Yen, Tzu-Ping; Chen, Chien-Wen

2017-05-01

The generation of linear photonic nanojet using core-shell optical microfiber is demonstrated numerically and experimentally in the visible light region. The power flow patterns for the core-shell optical microfiber are calculated by using the finite-difference time-domain method. The focusing properties of linear photonic nanojet are evaluated in terms of length and width along propagation and transversal directions. In experiment, the silica optical fiber is etched chemically down to 6 μm diameter and coated with metallic thin film by using glancing angle deposition. We show that the linear photonic nanojet is enhanced clearly by metallic shell due to surface plasmon polaritons. The large-area superresolution imaging can be performed by using a core-shell optical microfiber in the far-field system. The potential applications of this core-shell optical microfiber include micro-fluidics and nano-structure measurements.

Increasing Entanglement between Gaussian States by Coherent Photon Subtraction

DEFF Research Database (Denmark)

Ourjoumtsev, Alexei; Dantan, Aurelien Romain; Tualle Brouri, Rosa

2007-01-01

We experimentally demonstrate that the entanglement between Gaussian entangled states can be increased by non-Gaussian operations. Coherent subtraction of single photons from Gaussian quadrature-entangled light pulses, created by a nondegenerate parametric amplifier, produces delocalized states...

Hard photons in W pair production at LEP 2

International Nuclear Information System (INIS)

Oldenborgh, G.J. van

1996-01-01

The properties of hard photon radiation in W pair production at LEP 2 are studied, with emphasis on the energy loss relevant to the W mass measurement. We use a combination of the exact one-photon matrix element and leading logarithmic structure functions. Defining unobservable, observable and initial-state photons in the phase space, it is shown that neither the one-photon matrix element nor the leading logarithmic structure functions alone give an adequate description of the energy loss due to observable or initial-state photons. An event generator based on these calculations is available. (orig.)

On-demand semiconductor single-photon source with near-unity indistinguishability.

Science.gov (United States)

He, Yu-Ming; He, Yu; Wei, Yu-Jia; Wu, Dian; Atatüre, Mete; Schneider, Christian; Höfling, Sven; Kamp, Martin; Lu, Chao-Yang; Pan, Jian-Wei

2013-03-01

Single-photon sources based on semiconductor quantum dots offer distinct advantages for quantum information, including a scalable solid-state platform, ultrabrightness and interconnectivity with matter qubits. A key prerequisite for their use in optical quantum computing and solid-state networks is a high level of efficiency and indistinguishability. Pulsed resonance fluorescence has been anticipated as the optimum condition for the deterministic generation of high-quality photons with vanishing effects of dephasing. Here, we generate pulsed single photons on demand from a single, microcavity-embedded quantum dot under s-shell excitation with 3 ps laser pulses. The π pulse-excited resonance-fluorescence photons have less than 0.3% background contribution and a vanishing two-photon emission probability. Non-postselective Hong-Ou-Mandel interference between two successively emitted photons is observed with a visibility of 0.97(2), comparable to trapped atoms and ions. Two single photons are further used to implement a high-fidelity quantum controlled-NOT gate.

Quantum state propagation in linear photonic bandgap structures

International Nuclear Information System (INIS)

Severini, S; Tricca, D; Sibilia, C; Bertolotti, M; Perina, Jan

2004-01-01

In this paper we investigate the propagation of a generic quantum state in a corrugated waveguide, which reproduces a photonic bandgap structure. We find the conditions that assure the outcoming state to preserve the quantum properties of the incoming state. Then, focusing on a particular quantum state (realized by two counter-propagating coherent states), we study the possibility of preserving the quantum properties of this particular double coherent state even in the presence of absorption phenomena during propagation in the structure

Scheme for generating the singlet state of three atoms trapped in distant cavities coupled by optical fibers

Energy Technology Data Exchange (ETDEWEB)

Wang, Dong-Yang [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wen, Jing-Ji [College of Foundation Science, Harbin University of Commerce, Harbin, Heilongjiang 150028 (China); Bai, Cheng-Hua; Hu, Shi; Cui, Wen-Xue [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wang, Hong-Fu, E-mail: hfwang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhu, Ai-Dong [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhang, Shou, E-mail: szhang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China)

2015-09-15

An effective scheme is proposed to generate the singlet state with three four-level atoms trapped in three distant cavities connected with each other by three optical fibers, respectively. After a series of appropriate atom–cavity interactions, which can be arbitrarily controlled via the selective pairing of Raman transitions and corresponding optical switches, a three-atom singlet state can be successfully generated. The influence of atomic spontaneous decay, photon leakage of cavities and optical fibers on the fidelity of the state is numerically simulated showing that the three-atom singlet state can be generated with high fidelity by choosing the experimental parameters appropriately.

Manipulation of photons at the surface of three-dimensional photonic crystals.

Science.gov (United States)

Ishizaki, Kenji; Noda, Susumu

2009-07-16

In three-dimensional (3D) photonic crystals, refractive-index variations with a periodicity comparable to the wavelength of the light passing through the crystal give rise to so-called photonic bandgaps, which are analogous to electronic bandgaps for electrons moving in the periodic electrostatic potential of a material's crystal structure. Such 3D photonic bandgap crystals are envisioned to become fundamental building blocks for the control and manipulation of photons in optical circuits. So far, such schemes have been pursued by embedding artificial defects and light emitters inside the crystals, making use of 3D bandgap directional effects. Here we show experimentally that photons can be controlled and manipulated even at the 'surface' of 3D photonic crystals, where 3D periodicity is terminated, establishing a new and versatile route for photon manipulation. By making use of an evanescent-mode coupling technique, we demonstrate that 3D photonic crystals possess two-dimensional surface states, and we map their band structure. We show that photons can be confined and propagate through these two-dimensional surface states, and we realize their localization at arbitrary surface points by designing artificial surface-defect structures through the formation of a surface-mode gap. Surprisingly, the quality factors of the surface-defect mode are the largest reported for 3D photonic crystal nanocavities (Q up to approximately 9,000). In addition to providing a new approach for photon manipulation by photonic crystals, our findings are relevant for the generation and control of plasmon-polaritons in metals and the related surface photon physics. The absorption-free nature of the 3D photonic crystal surface may enable new sensing applications and provide routes for the realization of efficient light-matter interactions.

Entangled, guided photon generation in (1+1)-dimensional photonic crystals

International Nuclear Information System (INIS)

Sciscione, L.; Centini, M.; Sibilia, C.; Bertolotti, M.; Scalora, M.

2006-01-01

A scheme based on photonic crystal technology is proposed as an ultrabright source of entangled photons on a miniaturized scale. The geometry consists of a multilayer microcavity, excited by a resonant pump frequency, such that the emitted photons are guided transversally to the direction of the incident pump. The entanglement occurs in direction, frequency, and polarization, and the bandwidth of the emitted photons is of the order of 1 nm. We propose a feasible design based on Al 0.3 Ga 0.7 As/Al 2 O 3 structures and predict an emission rate 10 5 pairs per second with 100 mW pump power. These results are promising for realization of chip and future quantum computer applications

Photonic arbitrary waveform generation applicable to multiband UWB communications.

Science.gov (United States)

Bolea, Mario; Mora, José; Ortega, Beatriz; Capmany, José

2010-12-06

A novel photonic structure for arbitrary waveform generation (AWG) is proposed based on the electrooptical intensity modulation of a broadband optical signal which is transmitted by a dispersive element and the optoelectrical processing is realized by combining an interferometric structure with balanced photodetection. The generated waveform can be fully reconfigured through the control of the optical source power spectrum and the interferometric structure. The use of balanced photodetection permits to remove the baseband component of the generated signal which is relevant in certain applications. We have theoretically described and experimentally demonstrated the feasibility of the system by means of the generation of different pulse shapes. Specifically, the proposed structure has been applicable to generate Multiband UWB signaling formats regarding to the FCC requirements in order to show the flexibility of the system.

Quantum optical signatures in strong-field laser physics: Infrared photon counting in high-order-harmonic generation.

Science.gov (United States)

Gonoskov, I A; Tsatrafyllis, N; Kominis, I K; Tzallas, P

2016-09-07

We analytically describe the strong-field light-electron interaction using a quantized coherent laser state with arbitrary photon number. We obtain a light-electron wave function which is a closed-form solution of the time-dependent Schrödinger equation (TDSE). This wave function provides information about the quantum optical features of the interaction not accessible by semi-classical theories. With this approach we can reveal the quantum optical properties of high harmonic generation (HHG) process in gases by measuring the photon statistics of the transmitted infrared (IR) laser radiation. This work can lead to novel experiments in high-resolution spectroscopy in extreme-ultraviolet (XUV) and attosecond science without the need to measure the XUV light, while it can pave the way for the development of intense non-classical light sources.

Picosecond anti-Stokes generation in a photonic-crystal fiber for interferometric CARS microscopy

DEFF Research Database (Denmark)

Keiding, Søren Rud

2006-01-01

We generate tunable picosecond anti-Stokes pulses by four-wave mixing of two picosecond pump and Stokes pulse trains in a photonic-crystal fiber. The visible, spectrally narrow anti-Stokes pulses with shifts over 150 nm are generated without generating other spectral features. As a demonstration,...

Quantum interface between an atom and a photon

International Nuclear Information System (INIS)

Wilk, Tatjana

2008-02-01

A single atom strongly coupled to a high-finesse optical cavity is a versatile tool for quantum information processing. Utilized as a single-photon source, it allows one to generate single photons very efficiently in a well de ned spatio-temporal mode. In a first experiment, polarization-control over the photons is shown. A time-resolved two-photon interference experiment proves the indistinguishability of these photons - required in various quantum information processing schemes. Moreover, in a second experiment, entanglement between the polarization of the emitted photon and the population of the atomic Zeeman levels is created. Subsequent state mapping of the atomic state onto another photon results in a pair of polarization-entangled photons emitted one after the other from the cavity. Although these schemes are in principle possible in free space, the cavity boosts the efficiency by several orders of magnitude. (orig.)

Optimization of Tapered Photonic Crystal Fibers for Blue-Enhanced Supercontinuum Generation

DEFF Research Database (Denmark)

Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper

2012-01-01

Tapering of photonic crystal fibers is an effective way of shifting the dispersive wavelength edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for blue-enhanced supercontinuum generation....

Quantum properties of a superposition of squeezed displaced two-mode vacuum and single-photon states

International Nuclear Information System (INIS)

El-Orany, Faisal A A; Obada, A-S F; M Asker, Zafer; Perina, J

2009-01-01

In this paper, we study some quantum properties of a superposition of displaced squeezed two-mode vacuum and single-photon states, such as the second-order correlation function, the Cauchy-Schwarz inequality, quadrature squeezing, quasiprobability distribution functions and purity. These type of states include two mechanisms, namely interference in phase space and entanglement. We show that these states can exhibit sub-Poissonian statistics, squeezing and deviate from the classical Cauchy-Schwarz inequality. Moreover, the amount of entanglement in the system can be increased by increasing the squeezing mechanism. In the framework of the quasiprobability distribution functions, we show that the single-mode state can tend to the thermal state based on the correlation mechanism. A generation scheme for such states is given.

High-Harmonic Generation in Solids with and without Topological Edge States

DEFF Research Database (Denmark)

Bauer, Dieter; Hansen, Kenneth Christian Klochmann

2018-01-01

High-harmonic generation in the two topological phases of a finite, one-dimensional, periodic structure is investigated using a self-consistent time-dependent density functional theory approach. For harmonic photon energies smaller than the band gap, the harmonic yield is found to differ by up...... to 14 orders of magnitude for the two topological phases. This giant topological effect is explained by the degree of destructive interference in the harmonic emission of all valence-band (and edge-state) electrons, which strongly depends on whether or not topological edge states are present...

Four Pion Final States with Tagged Photons at Electron Positron Colliders

CERN Document Server

Czyz, H

2001-01-01

A Monte Carlo generator has been constructed to simulate the reaction e^+e^- \\to \\gamma + 4 \\pi, where the photon is assumed to be observed in the detector. Isospin relations between the amplitudes governing tau decays into four pions and electron positron annihilation into four pions respectively have been found which allow to determine all four modes after the amplitude for the \\pi^+\\pi^-2\\pi^0 channel has been fixed. The kinematic breaking of these isospin relations as a consequence of the \\pi^- -- \\pi^0 mass difference has also been investigated. The program is constructed in analogy to an earlier one simulating e^+e^- \\to \\gamma + 2 \\pi. However, it does not include final state radiation from the charged pions. Additional collinear photon radiation has been incorporated with the technique of structure functions. Predictions are presented for cms energies of 1GeV, 3GeV and 10GeV, corresponding to the energies of DAPHNE, BEBC and of B-meson factories. Using this program it is demonstrated that, even after ...

Observation of squeezed states with strong photon-number oscillations

International Nuclear Information System (INIS)

Mehmet, Moritz; Vahlbruch, Henning; Lastzka, Nico; Danzmann, Karsten; Schnabel, Roman

2010-01-01

Squeezed states of light constitute an important nonclassical resource in the field of high-precision measurements, for example, gravitational wave detection, as well as in the field of quantum information, for example, for teleportation, quantum cryptography, and distribution of entanglement in quantum computation networks. Strong squeezing in combination with high purity, high bandwidth, and high spatial mode quality is desirable in order to achieve significantly improved performances contrasting any classical protocols. Here we report on the observation of 11.5 dB of squeezing, together with relatively high state purity corresponding to a vacuum contribution of less than 5%, and a squeezing bandwidth of about 170 MHz. The analysis of our squeezed states reveals a significant production of higher-order pairs of quantum-correlated photons and the existence of strong photon-number oscillations.

One-way propagation of bulk states and robust edge states in photonic crystals with broken inversion and time-reversal symmetries

Science.gov (United States)

Lu, Jin-Cheng; Chen, Xiao-Dong; Deng, Wei-Min; Chen, Min; Dong, Jian-Wen

2018-07-01

The valley is a flexible degree of freedom for light manipulation in photonic systems. In this work, we introduce the valley concept in magnetic photonic crystals with broken inversion symmetry. One-way propagation of bulk states is demonstrated by exploiting the pseudo-gap where bulk states only exist at one single valley. In addition, the transition between Hall and valley-Hall nontrivial topological phases is also studied in terms of the competition between the broken inversion and time-reversal symmetries. At the photonic boundary between two topologically distinct photonic crystals, we illustrate the one-way propagation of edge states and demonstrate their robustness against defects.

Free-Space Quantum Key Distribution with a High Generation Rate Potassium Titanyl Phosphate Waveguide Photon-Pair Source

Science.gov (United States)

Wilson, Jeffrey D.; Chaffee, Dalton W.; Wilson, Nathaniel C.; Lekki, John D.; Tokars, Roger P.; Pouch, John J.; Roberts, Tony D.; Battle, Philip; Floyd, Bertram M.; Lind, Alexander J.;

Recent photon results from ATLAS

CERN Document Server

Glasman, Claudia; The ATLAS collaboration

2017-01-01

The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the gluon density function of the proton. The ATLAS collaboration has performed precise measurements of the inclusive production o f isolated prompt photons at a center-of-mass energy of 13 TeV, differential in both rap idity and the photon transverse momentum. In addition, the integrated and differential c ross sections for isolated photon pair production 8 TeV have been measured. The results are compared with state-of-the-art theory predictions at NLO in QCD and with predictions of several MC generators.

Manipulation of a two-photon pump in superconductor - semiconductor heterostructures

Science.gov (United States)

Orth, Peter P.; Baireuther, Paul; Vekhter, Ilya; Schmalian, Joerg

2014-03-01

We investigate the photon statistics, entanglement and squeezing of a pn-junction sandwiched between two superconducting leads, and show that such an electrically-driven photon pump generates correlated and entangled pairs of photons. In particular, we demonstrate that the squeezing of the fluctuations in the quadrature amplitudes of the emitted light can be manipulated by changing the relative phase of the order parameters of the superconductors. This reveals how macroscopic coherence of the superconducting state can be used to tailor the properties of a two-photon state.

Two-photon interference of weak coherent laser pulses recalled from separate solid-state quantum memories

Science.gov (United States)

Jin, Jeongwan; Slater, Joshua A.; Saglamyurek, Erhan; Sinclair, Neil; George, Mathew; Ricken, Raimund; Oblak, Daniel; Sohler, Wolfgang; Tittel, Wolfgang

2013-08-01

Quantum memories allowing reversible transfer of quantum states between light and matter are central to quantum repeaters, quantum networks and linear optics quantum computing. Significant progress regarding the faithful transfer of quantum information has been reported in recent years. However, none of these demonstrations confirm that the re-emitted photons remain suitable for two-photon interference measurements, such as C-NOT gates and Bell-state measurements, which constitute another key ingredient for all aforementioned applications. Here, using pairs of laser pulses at the single-photon level, we demonstrate two-photon interference and Bell-state measurements after either none, one or both pulses have been reversibly mapped to separate thulium-doped lithium niobate waveguides. As the interference is always near the theoretical maximum, we conclude that our solid-state quantum memories, in addition to faithfully mapping quantum information, also preserve the entire photonic wavefunction. Hence, our memories are generally suitable for future applications of quantum information processing that require two-photon interference.

Two-photon interference of weak coherent laser pulses recalled from separate solid-state quantum memories.

Science.gov (United States)

Jin, Jeongwan; Slater, Joshua A; Saglamyurek, Erhan; Sinclair, Neil; George, Mathew; Ricken, Raimund; Oblak, Daniel; Sohler, Wolfgang; Tittel, Wolfgang

2013-01-01

Quantum memories allowing reversible transfer of quantum states between light and matter are central to quantum repeaters, quantum networks and linear optics quantum computing. Significant progress regarding the faithful transfer of quantum information has been reported in recent years. However, none of these demonstrations confirm that the re-emitted photons remain suitable for two-photon interference measurements, such as C-NOT gates and Bell-state measurements, which constitute another key ingredient for all aforementioned applications. Here, using pairs of laser pulses at the single-photon level, we demonstrate two-photon interference and Bell-state measurements after either none, one or both pulses have been reversibly mapped to separate thulium-doped lithium niobate waveguides. As the interference is always near the theoretical maximum, we conclude that our solid-state quantum memories, in addition to faithfully mapping quantum information, also preserve the entire photonic wavefunction. Hence, our memories are generally suitable for future applications of quantum information processing that require two-photon interference.

Study of Raman-free photon pair generation using inter-modal four-wave mixing in a few-mode silica fiber

DEFF Research Database (Denmark)

Friis, Søren Michael Mørk; Christensen, Jesper Bjerge; Koefoed, Jacob Gade

2017-01-01

Single-photon sources are key components in applications of photonic quantum technologies such as quantum key distribution (QKD) [1]. One way of realizing single-photon sources is generation of photon pairs (PP) using spontaneous four-wave mixing (FWM): two photons from a pump p annihilate...... and create two side-band photons at frequencies determined partly by the energy conservation 2ωρ = ω1 + ω2, where ωp,ω1,ω2 are the frequencies of the pump and the two side-bands, respectively, and partly by the phase-matching condition. PP generated spontaneously arrive at indeterministic times but even so......, they are useful for QKD because one of the photons can be heralded by detecting the other. The heralded photons are then used for transmitting the quantum key....

Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.

Deformed two-photon squeezed states in noncommutative space

International Nuclear Information System (INIS)

Zhang Jianzu

2004-01-01

Recent studies on nonperturbation aspects of noncommutative quantum mechanics explored a new type of boson commutation relations at the deformed level, described by deformed annihilation-creation operators in noncommutative space. This correlated boson commutator correlates different degrees of freedom, and shows an essential influence on dynamics. This Letter devotes to the development of formalism of deformed two-photon squeezed states in noncommutative space. General representations of deformed annihilation-creation operators and the consistency condition for the electromagnetic wave with a single mode of frequency in noncommunicative space are obtained. Two-photon squeezed states are studied. One finds that variances of the dimensionless Hermitian quadratures of the annihilation operator in one degree of freedom include variances in the other degree of freedom. Such correlations show the new feature of spatial noncommutativity and allow a deeper understanding of the correlated boson commutator

Challenges and opportunities for the next generation of photon regeneration experiments

International Nuclear Information System (INIS)

Ringwald, Andreas

2010-03-01

Photon regeneration experiments searching for signatures of oscillations of photons into hypothetical very weakly interacting ultra-light particles, such as axions, axion-like and hiddensector particles, have improved their sensitivity considerably in recent years. Important progress in laser and detector technology as well as recycling of available magnets from accelerators may allow a big further step in sensitivity such that, for the first time, laser light shining through a wall experiments will explore territory in parameter space that has not been excluded yet by astrophysics and cosmology.We review these challenges and opportunities for the next generation experiments. (orig.)

Generation of multiparticle three-dimensional entanglement state via adiabatic passage

International Nuclear Information System (INIS)

Wu Xi; Chen Zhi-Hua; Ye Ming-Yong; Chen Yue-Hua; Lin Xiu-Min

2013-01-01

A scheme is proposed for generating a multiparticle three-dimensional entangled state by appropriately adiabatic evolutions, where atoms are respectively trapped in separated cavities so that individual addressing is needless. In the ideal case, losses due to the spontaneous transition of an atom and the excitation of photons are efficiently suppressed since atoms are all in ground states and the fields remain in a vacuum state. Compared with the previous proposals, the present scheme reduces its required operation time via simultaneously controlling four classical fields. This advantage would become even more obvious as the number of atoms increases. The experimental feasibility is also discussed. The successful preparation of a high-dimensional multiparticle entangled state among distant atoms provides better prospects for quantum communication and distributed quantum computation. (general)

Probabilistic teleportation scheme of two-mode entangled photon states by using linear optic element

Institute of Scientific and Technical Information of China (English)

XIANG Shao-hua

2003-01-01

A scheme for teleporting two-mode entangled photon states with the successful probability 33.3% is proposed. In the scheme, the teleporte d qubit is two-mode photon entangled states, and two pairs of EPR pair are used as quantum channel between a sender and a receiver. This procedure is achieved by using two 50/50 symmetric beam splitters and four photon number detectors wit h the help of classical information.

Parametric source of two-photon states with a tunable degree of entanglement and mixing: Experimental preparation of Werner states and maximally entangled mixed states

International Nuclear Information System (INIS)

Cinelli, C.; Di Nepi, G.; De Martini, F.; Barbieri, M.; Mataloni, P.

2004-01-01

A parametric source of polarization-entangled photon pairs with striking spatial characteristics is reported. The distribution of the output electromagnetic k modes excited by spontaneous parametric down-conversion and coupled to the output detectors can be very broad. Using these states realized over a full entanglement ring output distribution, the nonlocal properties of the generated entanglement have been tested by standard Bell measurements and by Ou-Mandel interferometry. A 'mode-patchwork' technique based on the quantum superposition principle is adopted to synthesize in a straightforward and reliable way any kind of mixed state, of large conceptual and technological interest in modern quantum information. Tunable Werner states and maximally entangled mixed states have indeed been created by this technique and investigated by quantum tomography. A study of the entropic and nonlocal properties of these states has been undertaken experimentally and theoretically, by a unifying variational approach

Quantum and classical control of single photon states via a mechanical resonator

International Nuclear Information System (INIS)

Basiri-Esfahani, Sahar; Myers, Casey R; Combes, Joshua; Milburn, G J

2016-01-01

Optomechanical systems typically use light to control the quantum state of a mechanical resonator. In this paper, we propose a scheme for controlling the quantum state of light using the mechanical degree of freedom as a controlled beam splitter. Preparing the mechanical resonator in non-classical states enables an optomechanical Stern–Gerlach interferometer. When the mechanical resonator has a small coherent amplitude it acts as a quantum control, entangling the optical and mechanical degrees of freedom. As the coherent amplitude of the resonator increases, we recover single photon and two-photon interference via a classically controlled beam splitter. The visibility of the two-photon interference is particularly sensitive to coherent excitations in the mechanical resonator and this could form the basis of an optically transduced weak-force sensor. (paper)

Engineering spectrally unentangled photon pairs from nonlinear microring resonators by pump manipulation

DEFF Research Database (Denmark)

Christensen, Jesper Bjerge; Koefoed, Jacob Gade; Rottwitt, Karsten

2018-01-01

The future of integrated quantum photonics relies heavily on the ability to engineer refined methods for preparing the quantum states needed to implement various quantum protocols. An important example of such states is quantum-correlated photon pairs, which can be efficiently generated using spo...

High coincidence-to-accidental ratio continuous-wave photon-pair generation in a grating-coupled silicon strip waveguide

DEFF Research Database (Denmark)

Guo, Kai; Christensen, Erik Nicolai; Christensen, Jesper Bjerge

2017-01-01

We demonstrate a very high coincidence-to-accidental ratio of 673 using continuous-wave photon-pair generation in a silicon strip waveguide through spontaneous four-wave mixing. This result is obtained by employing on-chip photonic-crystal-based grating couplers for both low-loss fiber......-to-chip coupling and on-chip suppression of generated spontaneous Raman scattering noise. We measure a minimum heralded second-order correlation of g(H)((2)) (0) = 0.12, demonstrating that our source operates in the single- photon regime with low noise. (C) 2017 The Japan Society of Applied Physics...

Engineering two-photon high-dimensional states through quantum interference

CSIR Research Space (South Africa)

Zhang, YI

2016-02-01

Full Text Available . ngled photon pairs (see p a nonlinear crystal to ersion (SPDC). At the tate (6) ℓ¼1 stat th , w from ℓ = 0. The subscripts A and B la R E S EARCH ART I C L E o n February 28, 2016 http://advances.sciencem ag.org/ D ow nloaded from stitute of Photonics... contribution from the ℓ = 1, 2, and 3 subspaces in this six-dimensional state (36 × 36 matrix). (B) The state after the filter, which in principle is given byd01jY � 1 〉 þ d 0 3jY � 3 〉; the contribution from the ℓ = 2 subspace is 3.8 ± 0.2% of its original...

FY 1998 annual summary report on photon measuring/processing techniques. Development of highly functional maintenance techniques for power generating facilities; 1998 nendo foton keisoku kako gijutsu. Hatsuden shisetsuyo kokino maintenance gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The objectives are set to develop the techniques for non-destructive measurement of conditions of facility portions, especially those exposed to severe environments, e.g., elevated temperature and pressure, over a wide range; the techniques for measurement of leakage of, e.g., gases, at high sensitivity; the techniques of laser-aided welding and surface-modification treatment for the members exposed to severe conditions; and the techniques for generating photon beams of high quality and energy density as the tools therefor, in order to improve reliability and maintenance efficiency of power generating facilities. The R and D themes are microscopic processing technology: fabrication technology for functional micro-composite circuits; in-situ status measuring technology: gas concentration/component measurement technology, and photon wavefront compensation device technology; non-destructive composition measuring technology: high-sensitivity detection technology using short-wavelength photons; high-power all-solid-state laser technology: rod-type laser and slab-type laser; tightly-focusing all-solid-state laser technology: high-energy pulse, high-quality laser; and comprehensive investigation of photonics engineering: investigation for photon-applied measurement technologies. (NEDO)

Study of a positron source generated by photons from ultrarelativistic channeled particles

International Nuclear Information System (INIS)

Chehab, R.; Couchot, F.; Nyaiesh, A.R.; Richard, F.; Artru, X.

1989-03-01

Radiation by channeled electrons in Germanium and Silicon crystals along the axis is studied as a very promising photon source of small angular divergence for positron generation in amorphous targets. Radiation rates for different crystal lengths - from some tenths of mm to 10 mm - and two electron incident energies, 5 and 20 GeV, are considered and a comparison between the two crystals is presented. Thermic behaviour of the crystal under incidence of bunches of 10 10 electrons is also examined. The corresponding positron yields for tungsten amorphous converters - of 0.5 and 1 X o thickness - are calculated considering the case of a Germanium photon generator. Assuming a large acceptance optical matching system as the adiabatic device of the SLC, accepted positrons are evaluated and positron yields larger than 1 e + /e - are obtained

Deterministic multimode photonic device for quantum-information processing

DEFF Research Database (Denmark)

Nielsen, Anne E. B.; Mølmer, Klaus

2010-01-01

We propose the implementation of a light source that can deterministically generate a rich variety of multimode quantum states. The desired states are encoded in the collective population of different ground hyperfine states of an atomic ensemble and converted to multimode photonic states by exci...

Photon wave function formalism for analysis of Mach–Zehnder interferometer and sum-frequency generation

Energy Technology Data Exchange (ETDEWEB)

Ritboon, Atirach, E-mail: atirach.3.14@gmail.com [School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai 90112 (Thailand); Daengngam, Chalongrat, E-mail: chalongrat.d@psu.ac.th [Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai 90112 (Thailand); Pengpan, Teparksorn, E-mail: teparksorn.p@psu.ac.th [Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai 90112 (Thailand)

2016-08-15

Biakynicki-Birula introduced a photon wave function similar to the matter wave function that satisfies the Schrödinger equation. Its second quantization form can be applied to investigate nonlinear optics at nearly full quantum level. In this paper, we applied the photon wave function formalism to analyze both linear optical processes in the well-known Mach–Zehnder interferometer and nonlinear optical processes for sum-frequency generation in dispersive and lossless medium. Results by photon wave function formalism agree with the well-established Maxwell treatments and existing experimental verifications.

Photon wave function formalism for analysis of Mach–Zehnder interferometer and sum-frequency generation

International Nuclear Information System (INIS)

Ritboon, Atirach; Daengngam, Chalongrat; Pengpan, Teparksorn

2016-01-01

Biakynicki-Birula introduced a photon wave function similar to the matter wave function that satisfies the Schrödinger equation. Its second quantization form can be applied to investigate nonlinear optics at nearly full quantum level. In this paper, we applied the photon wave function formalism to analyze both linear optical processes in the well-known Mach–Zehnder interferometer and nonlinear optical processes for sum-frequency generation in dispersive and lossless medium. Results by photon wave function formalism agree with the well-established Maxwell treatments and existing experimental verifications.

Quantum teleportation from a telecom-wavelength photon to a solid-state quantum memory

Energy Technology Data Exchange (ETDEWEB)

Bussieres, Felix [Group of Applied Physics, University of Geneva (Switzerland)

2014-07-01

Quantum teleportation is a cornerstone of quantum information science due to its essential role in several important tasks such as the long-distance transmission of quantum information using quantum repeaters. In this context, a challenge of paramount importance is the distribution of entanglement between remote nodes, and to use this entanglement as a resource for long-distance light-to-matter quantum teleportation. In this talk I will report on the demonstration of quantum teleportation of the polarization state of a telecom-wavelength photon onto the state of a solid-state quantum memory. Entanglement is established between a rare-earth-ion doped crystal storing a single photon that is polarization-entangled with a flying telecom-wavelength photon. The latter is jointly measured with another flying qubit carrying the polarization state to be teleported, which heralds the teleportation. The fidelity of the polarization state of the photon retrieved from the memory is shown to be greater than the maximum fidelity achievable without entanglement, even when the combined distances travelled by the two flying qubits is 25 km of standard optical fibre. This light-to-matter teleportation channel paves the way towards long-distance implementations of quantum networks with solid-state quantum memories.

System and method for clock synchronization and position determination using entangled photon pairs

Science.gov (United States)

Shih, Yanhua (Inventor)

2010-01-01

A system and method for clock synchronization and position determination using entangled photon pairs is provided. The present invention relies on the measurement of the second order correlation function of entangled states. Photons from an entangled photon source travel one-way to the clocks to be synchronized. By analyzing photon registration time histories generated at each clock location, the entangled states allow for high accuracy clock synchronization as well as high accuracy position determination.

Generation of Atomic Greenberger-Horne-Zeilinger States Based on Faraday Rotation

International Nuclear Information System (INIS)

Liang Honghui; Li Xinghua

2010-01-01

Based on the input-output relation of the cavity and the Faraday Rotation mechanism, we propose a scheme for generating the n-atom Greenberger-Horne-Zeilinger state. In the scheme, the n-atom trapped respectively in n spatially separate cavities would be entangled with the photons going through the atom-cavity system. The successful probabilities of our protocol approach unity in the ideal case. What is more, no requirement for separately addressing further lowers experimental difficulties. (general)

Efficient generation of photonic entanglement and multiparty quantum communication

Energy Technology Data Exchange (ETDEWEB)

Trojek, Pavel

2007-09-15

This thesis deals largely with the problem of efficient generation of photonic entanglement with the principal aim of developing a bright source of polarization-entangled photon pairs, which meets the requirements for reliable and economic operation of quantum communication prototypes and demonstrators. Our approach uses a cor-related photon-pair emission in nonlinear process of spontaneous parametric downconversion pumped by light coming from a compact and cheap blue laser diode. Two alternative source configurations are examined within the thesis. The first makes use of a well established concept of degenerate non-collinear emission from a single type-II nonlinear crystal and the second relies on a novel method where the emissions from two adjacent type-I phase-matched nonlinear crystals operated in collinear non-degenerate regime are coherently overlapped. The latter approach showed to be more effective, yielding a total detected rate of almost 10{sup 6} pairs/s at >98% quantum interference visibility of polarization correlations. The second issue addressed within the thesis is the simplification and practical implementation of quantum-assisted solutions to multiparty communication tasks. We show that entanglement is not the only non-classical resource endowing the quantum multiparty information processing its power. Instead, only the sequential communication and transformation of a single qubit can be sufficient to accomplish certain tasks. This we prove for two distinct communication tasks, secret sharing and communication complexity. Whereas the goal of the first is to split a cryptographic key among several parties in a way that its reconstruction requires their collaboration, the latter aims at reducing the amount of communication during distributed computational tasks. Importantly, our qubitassisted solutions to the problems are feasible with state-of-the-art technology. This we clearly demonstrate in the laboratory implementation for 6 and 5 parties

Efficient generation of photonic entanglement and multiparty quantum communication

International Nuclear Information System (INIS)

Trojek, Pavel

2007-09-01

This thesis deals largely with the problem of efficient generation of photonic entanglement with the principal aim of developing a bright source of polarization-entangled photon pairs, which meets the requirements for reliable and economic operation of quantum communication prototypes and demonstrators. Our approach uses a cor-related photon-pair emission in nonlinear process of spontaneous parametric downconversion pumped by light coming from a compact and cheap blue laser diode. Two alternative source configurations are examined within the thesis. The first makes use of a well established concept of degenerate non-collinear emission from a single type-II nonlinear crystal and the second relies on a novel method where the emissions from two adjacent type-I phase-matched nonlinear crystals operated in collinear non-degenerate regime are coherently overlapped. The latter approach showed to be more effective, yielding a total detected rate of almost 10 6 pairs/s at >98% quantum interference visibility of polarization correlations. The second issue addressed within the thesis is the simplification and practical implementation of quantum-assisted solutions to multiparty communication tasks. We show that entanglement is not the only non-classical resource endowing the quantum multiparty information processing its power. Instead, only the sequential communication and transformation of a single qubit can be sufficient to accomplish certain tasks. This we prove for two distinct communication tasks, secret sharing and communication complexity. Whereas the goal of the first is to split a cryptographic key among several parties in a way that its reconstruction requires their collaboration, the latter aims at reducing the amount of communication during distributed computational tasks. Importantly, our qubitassisted solutions to the problems are feasible with state-of-the-art technology. This we clearly demonstrate in the laboratory implementation for 6 and 5 parties

Spin-photon entangling diode

DEFF Research Database (Denmark)

Flindt, Christian; Sørensen, A. S.; Lukin, M. D.

2007-01-01

We propose a semiconductor device that can electrically generate entangled electron spin-photon states, providing a building block for entanglement of distant spins. The device consists of a p-i-n diode structure that incorporates a coupled double quantum dot. We show that electronic control of t...

Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: A peculiar role of geometry

Energy Technology Data Exchange (ETDEWEB)

Aryanpour, Karan [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Shukla, Alok [Department of Physics, Indian Institute of Technology, Powai, Mumbai 400076 (India); Mazumdar, Sumit [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States)

2014-03-14

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D{sub 6h} point group symmetry versus ovalene with D{sub 2h} symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D{sub 6h} group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D{sub 2h} ovalene but not in those with D{sub 6h} symmetry.

Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: A peculiar role of geometry

International Nuclear Information System (INIS)

Aryanpour, Karan; Shukla, Alok; Mazumdar, Sumit

2014-01-01

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D 6h point group symmetry versus ovalene with D 2h symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D 6h group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D 2h ovalene but not in those with D 6h symmetry

Electron correlations and two-photon states in polycyclic aromatic hydrocarbon molecules: a peculiar role of geometry.

Science.gov (United States)

Aryanpour, Karan; Shukla, Alok; Mazumdar, Sumit

2014-03-14

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene, and circumcoronene, all possessing D(6h) point group symmetry versus ovalene with D(2h) symmetry, within the Pariser-Parr-Pople model of interacting π-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitatively different from single-particle descriptions. More remarkably, a peculiar role of molecular geometry is found. The consequence of electron correlations is far stronger for ovalene, where the lowest spin-singlet two-photon state is a quantum superposition of pairs of lowest spin triplet states, as in the linear polyenes. The same is not true for D(6h) group hydrocarbons. Our work indicates significant covalent character, in valence bond language, of the ground state, the lowest spin triplet state and a few of the lowest two-photon states in D(2h) ovalene but not in those with D(6h) symmetry.

Influence of pump-field scattering on nonclassical-light generation in a photonic-band-gap nonlinear planar waveguide

International Nuclear Information System (INIS)

Perina, Jan Jr.; Sibilia, Concita; Tricca, Daniela; Bertolotti, Mario

2005-01-01

Optical parametric process occurring in a nonlinear planar waveguide can serve as a source of light with nonclassical properties. The properties of the generated fields are substantially modified by scattering of the nonlinearly interacting fields in a photonic-band-gap structure inside the waveguide. A general quantum model of linear operator amplitude corrections to the amplitude mean values and its numerical analysis provide conditions for efficient squeezed-light generation as well as generation of light with sub-Poissonian photon-number statistics. The destructive influence of phase mismatch of the nonlinear interaction can fully be compensated using a suitable photonic-band-gap structure inside the waveguide. Also an increase of the signal-to-noise ratio of the incident optical field can be reached in the waveguide

Deuterated silicon nitride photonic devices for broadband optical frequency comb generation

Science.gov (United States)

Chiles, Jeff; Nader, Nima; Hickstein, Daniel D.; Yu, Su Peng; Briles, Travis Crain; Carlson, David; Jung, Hojoong; Shainline, Jeffrey M.; Diddams, Scott; Papp, Scott B.; Nam, Sae Woo; Mirin, Richard P.

2018-04-01

We report and characterize low-temperature, plasma-deposited deuterated silicon nitride thin films for nonlinear integrated photonics. With a peak processing temperature less than 300$^\\circ$C, it is back-end compatible with pre-processed CMOS substrates. We achieve microresonators with a quality factor of up to $1.6\\times 10^6 $ at 1552 nm, and $>1.2\\times 10^6$ throughout $\\lambda$ = 1510 -- 1600 nm, without annealing or stress management. We then demonstrate the immediate utility of this platform in nonlinear photonics by generating a 1 THz free spectral range, 900-nm-bandwidth modulation-instability microresonator Kerr comb and octave-spanning, supercontinuum-broadened spectra.

Optimization of anisotropic photonic density of states for Raman cooling of solids

Science.gov (United States)

Chen, Yin-Chung; Ghosh, Indronil; Schleife, André; Carney, P. Scott; Bahl, Gaurav

2018-04-01

Optical refrigeration of solids holds tremendous promise for applications in thermal management. It can be achieved through multiple mechanisms including inelastic anti-Stokes Brillouin and Raman scattering. However, engineering of these mechanisms remains relatively unexplored. The major challenge lies in the natural unfavorable imbalance in transition rates for Stokes and anti-Stokes scattering. We consider the influence of anisotropic photonic density of states on Raman scattering and derive expressions for cooling in such photonically anisotropic systems. We demonstrate optimization of the Raman cooling figure of merit considering all possible orientations for the material crystal and two example photonic crystals. We find that the anisotropic description of the photonic density of states and the optimization process is necessary to obtain the best Raman cooling efficiency for systems having lower symmetry. This general result applies to a wide array of other laser cooling methods in the presence of anisotropy.

Generation of a Kind of Displaced Thermal States in the Diffusion Process and its Statistical Properties

Science.gov (United States)

Xiang-Guo, Meng; Hong-Yi, Fan; Ji-Suo, Wang

2018-04-01

This paper proposes a kind of displaced thermal states (DTS) and explores how this kind of optical field emerges using the entangled state representation. The results show that the DTS can be generated by a coherent state passing through a diffusion channel with the diffusion coefficient ϰ only when there exists κ t = (e^{\\hbar ν /kBT} - 1 )^{-1}. Also, its statistical properties, such as mean photon number, Wigner function and entropy, are investigated.

Frequency-bin entanglement of ultra-narrow band non-degenerate photon pairs

Science.gov (United States)

Rieländer, Daniel; Lenhard, Andreas; Jime`nez Farìas, Osvaldo; Máttar, Alejandro; Cavalcanti, Daniel; Mazzera, Margherita; Acín, Antonio; de Riedmatten, Hugues

2018-01-01

We demonstrate frequency-bin entanglement between ultra-narrowband photons generated by cavity enhanced spontaneous parametric down conversion. Our source generates photon pairs in widely non-degenerate discrete frequency modes, with one photon resonant with a quantum memory material based on praseodymium doped crystals and the other photon at telecom wavelengths. Correlations between the frequency modes are analyzed using phase modulators and narrowband filters before detection. We show high-visibility two photon interference between the frequency modes, allowing us to infer a coherent superposition of the modes. We develop a model describing the state that we create and use it to estimate optimal measurements to achieve a violation of the Clauser-Horne (CH) Bell inequality under realistic assumptions. With these settings we perform a Bell test and show a significant violation of the CH inequality, thus proving the entanglement of the photons. Finally we demonstrate the compatibility with a quantum memory material by using a spectral hole in the praseodymium (Pr) doped crystal as spectral filter for measuring high-visibility two-photon interference. This demonstrates the feasibility of combining frequency-bin entangled photon pairs with Pr-based solid state quantum memories.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul

OpenAIRE

Alavi, S. E.; Soltanian, M. R. K.; Amiri, I. S.; Khalily, M.; Supa?at, A. S. M.; Ahmad, H.

2016-01-01

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides gene...

Frequency Control of Single Quantum Emitters in Integrated Photonic Circuits.

Science.gov (United States)

Schmidgall, Emma R; Chakravarthi, Srivatsa; Gould, Michael; Christen, Ian R; Hestroffer, Karine; Hatami, Fariba; Fu, Kai-Mei C

2018-02-14

Generating entangled graph states of qubits requires high entanglement rates with efficient detection of multiple indistinguishable photons from separate qubits. Integrating defect-based qubits into photonic devices results in an enhanced photon collection efficiency, however, typically at the cost of a reduced defect emission energy homogeneity. Here, we demonstrate that the reduction in defect homogeneity in an integrated device can be partially offset by electric field tuning. Using photonic device-coupled implanted nitrogen vacancy (NV) centers in a GaP-on-diamond platform, we demonstrate large field-dependent tuning ranges and partial stabilization of defect emission energies. These results address some of the challenges of chip-scale entanglement generation.

Frequency Control of Single Quantum Emitters in Integrated Photonic Circuits

Science.gov (United States)

Schmidgall, Emma R.; Chakravarthi, Srivatsa; Gould, Michael; Christen, Ian R.; Hestroffer, Karine; Hatami, Fariba; Fu, Kai-Mei C.

2018-02-01

Generating entangled graph states of qubits requires high entanglement rates, with efficient detection of multiple indistinguishable photons from separate qubits. Integrating defect-based qubits into photonic devices results in an enhanced photon collection efficiency, however, typically at the cost of a reduced defect emission energy homogeneity. Here, we demonstrate that the reduction in defect homogeneity in an integrated device can be partially offset by electric field tuning. Using photonic device-coupled implanted nitrogen vacancy (NV) centers in a GaP-on-diamond platform, we demonstrate large field-dependent tuning ranges and partial stabilization of defect emission energies. These results address some of the challenges of chip-scale entanglement generation.

Qubit entanglement between ring-resonator photon-pair sources on a silicon chip

Science.gov (United States)

Silverstone, J. W.; Santagati, R.; Bonneau, D.; Strain, M. J.; Sorel, M.; O'Brien, J. L.; Thompson, M. G.

2015-01-01

Entanglement—one of the most delicate phenomena in nature—is an essential resource for quantum information applications. Scalable photonic quantum devices must generate and control qubit entanglement on-chip, where quantum information is naturally encoded in photon path. Here we report a silicon photonic chip that uses resonant-enhanced photon-pair sources, spectral demultiplexers and reconfigurable optics to generate a path-entangled two-qubit state and analyse its entanglement. We show that ring-resonator-based spontaneous four-wave mixing photon-pair sources can be made highly indistinguishable and that their spectral correlations are small. We use on-chip frequency demultiplexers and reconfigurable optics to perform both quantum state tomography and the strict Bell-CHSH test, both of which confirm a high level of on-chip entanglement. This work demonstrates the integration of high-performance components that will be essential for building quantum devices and systems to harness photonic entanglement on the large scale. PMID:26245267

Ultrafast photon number resolving detector with a temperature stabilized si multi pixel photon counter

International Nuclear Information System (INIS)

Song, Minsoo; Hong, Eugene; Won, Eunil; Yoon, Tai Hyun

2008-01-01

Quantum information science has been rapidly progressed and matured and matured thanks to the recent developments of the single photon detection technologies. Single photon detectors such as a Si avalanche photo diode(APD)in the infrared, an InGaAs/InP APD in the telecommunication band, and a super conducting transient edge sensor(TES)in the broad region of the spectrum have been widely used. Single photon detectors, however, operating at the ultraviolet to visible (370nm∼800nm)regions has not been actively investigated partly due to the lack of single photon and/or entangled photon sources and the lack of solid state single photon detectors. In this paper, we investigate the single photon detection characteristics of a Si multi pixel photon counter(MPPC), which has a high spectral responsivity between 300nm to 800nm, as a photon number resolving solid state detector. Figure 1 shows the schematic diagram of the single photon detection set up at 399nm by using a temperature stabilized Si MPPC. The output beam of the laser being properly attenuated is directed to the MPPC module, at which fixed number of photo electrons corresponding to incident individual photon are generated at Geiger mode of the Si APD pixels. The detected photo current is converted into a digital signal by using a fast analog to digital converter and a digital oscilloscope stores the time sequence of the photo currents. Figure 2 shows the accumulated charges collected by MPPC at∼10.deg.C showing a clear single photon and two photons peaks, respectively, separated by ∼5 sigma of the coincidence counts at the two output ports of a Mach Zender interferometer as a function of optical path length difference. The research was supported by Seoul R and BD program(NT070127)and by the KRISS

Ultrafast photon number resolving detector with a temperature stabilized si multi pixel photon counter

Energy Technology Data Exchange (ETDEWEB)

Song, Minsoo; Hong, Eugene; Won, Eunil; Yoon, Tai Hyun [Korea Univ., Seoul (Korea, Republic of)

2008-11-15

Quantum information science has been rapidly progressed and matured and matured thanks to the recent developments of the single photon detection technologies. Single photon detectors such as a Si avalanche photo diode(APD)in the infrared, an InGaAs/InP APD in the telecommunication band, and a super conducting transient edge sensor(TES)in the broad region of the spectrum have been widely used. Single photon detectors, however, operating at the ultraviolet to visible (370nm∼800nm)regions has not been actively investigated partly due to the lack of single photon and/or entangled photon sources and the lack of solid state single photon detectors. In this paper, we investigate the single photon detection characteristics of a Si multi pixel photon counter(MPPC), which has a high spectral responsivity between 300nm to 800nm, as a photon number resolving solid state detector. Figure 1 shows the schematic diagram of the single photon detection set up at 399nm by using a temperature stabilized Si MPPC. The output beam of the laser being properly attenuated is directed to the MPPC module, at which fixed number of photo electrons corresponding to incident individual photon are generated at Geiger mode of the Si APD pixels. The detected photo current is converted into a digital signal by using a fast analog to digital converter and a digital oscilloscope stores the time sequence of the photo currents. Figure 2 shows the accumulated charges collected by MPPC at∼10.deg.C showing a clear single photon and two photons peaks, respectively, separated by ∼5 sigma of the coincidence counts at the two output ports of a Mach Zender interferometer as a function of optical path length difference. The research was supported by Seoul R and BD program(NT070127)and by the KRISS.

Broadband photon pair generation in green fluorescent proteins through spontaneous four-wave mixing

Science.gov (United States)

Shi, Siyuan; Thomas, Abu; Corzo, Neil V.; Kumar, Prem; Huang, Yuping; Lee, Kim Fook

2016-01-01

Recent studies in quantum biology suggest that quantum mechanics help us to explore quantum processes in biological system. Here, we demonstrate generation of photon pairs through spontaneous four-wave mixing process in naturally occurring fluorescent proteins. We develop a general empirical method for analyzing the relative strength of nonlinear optical interaction processes in five different organic fluorophores. Our results indicate that the generation of photon pairs in green fluorescent proteins is subject to less background noises than in other fluorophores, leading to a coincidence-to-accidental ratio ~145. As such proteins can be genetically engineered and fused to many biological cells, our experiment enables a new platform for quantum information processing in a biological environment such as biomimetic quantum networks and quantum sensors. PMID:27076032

Setting Single Photon Detectors for Use with an Entangled Photon Distribution System

Science.gov (United States)

2017-12-01

EPA software). 5) If a TPI measurement is to be performed, the polarization of the PAs must first be adjusted to account for the birefringence of the... measurement of the entangled photon pairs generated by an entangled photon pair source require at least 2 SPDs operating at their highest possible...v 1. Introduction 1 2. Generation, Detection, and Measurement of Entangled Photon Pairs 1 2.1 Generation of Entangled Photon Pairs 2 2.2

Phonon-Assisted Two-Photon Interference from Remote Quantum Emitters.

Science.gov (United States)

Reindl, Marcus; Jöns, Klaus D; Huber, Daniel; Schimpf, Christian; Huo, Yongheng; Zwiller, Val; Rastelli, Armando; Trotta, Rinaldo

2017-07-12

Photonic quantum technologies are on the verge of finding applications in everyday life with quantum cryptography and quantum simulators on the horizon. Extensive research has been carried out to identify suitable quantum emitters and single epitaxial quantum dots have emerged as near-optimal sources of bright, on-demand, highly indistinguishable single photons and entangled photon-pairs. In order to build up quantum networks, it is essential to interface remote quantum emitters. However, this is still an outstanding challenge, as the quantum states of dissimilar "artificial atoms" have to be prepared on-demand with high fidelity and the generated photons have to be made indistinguishable in all possible degrees of freedom. Here, we overcome this major obstacle and show an unprecedented two-photon interference (visibility of 51 ± 5%) from remote strain-tunable GaAs quantum dots emitting on-demand photon-pairs. We achieve this result by exploiting for the first time the full potential of a novel phonon-assisted two-photon excitation scheme, which allows for the generation of highly indistinguishable (visibility of 71 ± 9%) entangled photon-pairs (fidelity of 90 ± 2%), enables push-button biexciton state preparation (fidelity of 80 ± 2%) and outperforms conventional resonant two-photon excitation schemes in terms of robustness against environmental decoherence. Our results mark an important milestone for the practical realization of quantum repeaters and complex multiphoton entanglement experiments involving dissimilar artificial atoms.

Quantum state propagation in linear photonic bandgap structures

Czech Academy of Sciences Publication Activity Database

Severini, S.; Tricca, S.; Sibilia, C.; Peřina, Jan

2004-01-01

Roč. 6, - (2004), s. 110-114 ISSN 1464-4266 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : photonic crystals * coupled mode theory * decoherence * quantum states propagation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.746, year: 2004

Direct Generation and Detection of Quantum Correlated Photons with 3.2 um Wavelength Spacing.

Science.gov (United States)

Sua, Yong Meng; Fan, Heng; Shahverdi, Amin; Chen, Jia-Yang; Huang, Yu-Ping

2017-12-13

Quantum correlated, highly non-degenerate photons can be used to synthesize disparate quantum nodes and link quantum processing over incompatible wavelengths, thereby constructing heterogeneous quantum systems for otherwise unattainable superior performance. Existing techniques for correlated photons have been concentrated in the visible and near-IR domains, with the photon pairs residing within one micron. Here, we demonstrate direct generation and detection of high-purity photon pairs at room temperature with 3.2 um wavelength spacing, one at 780 nm to match the rubidium D2 line, and the other at 3950 nm that falls in a transparent, low-scattering optical window for free space applications. The pairs are created via spontaneous parametric downconversion in a lithium niobate waveguide with specially designed geometry and periodic poling. The 780 nm photons are measured with a silicon avalanche photodiode, and the 3950 nm photons are measured with an upconversion photon detector using a similar waveguide, which attains 34% internal conversion efficiency. Quantum correlation measurement yields a high coincidence-to-accidental ratio of 54, which indicates the strong correlation with the extremely non-degenerate photon pairs. Our system bridges existing quantum technology to the challenging mid-IR regime, where unprecedented applications are expected in quantum metrology and sensing, quantum communications, medical diagnostics, and so on.

Photonic Ultra-Wideband 781.25-Mb/s Signal Generation and Transmission Incorporating Digital Signal Processing Detection

DEFF Research Database (Denmark)

Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

2009-01-01

The generation of photonic ultra-wideband (UWB) impulse signals using an uncooled distributed-feedback laser is proposed. For the first time, we experimentally demonstrate bit-for-bit digital signal processing (DSP) bit-error-rate measurements for transmission of a 781.25-Mb/s photonic UWB signal...

Generation and control of polarization-entangled photons from GaAs island quantum dots by an electric field.

Science.gov (United States)

Ghali, Mohsen; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo

2012-02-07

Semiconductor quantum dots are potential sources for generating polarization-entangled photons efficiently. The main prerequisite for such generation based on biexciton-exciton cascaded emission is to control the exciton fine-structure splitting. Among various techniques investigated for this purpose, an electric field is a promising means to facilitate the integration into optoelectronic devices. Here we demonstrate the generation of polarization-entangled photons from single GaAs quantum dots by an electric field. In contrast to previous studies, which were limited to In(Ga)As quantum dots, GaAs island quantum dots formed by a thickness fluctuation were used because they exhibit a larger oscillator strength and emit light with a shorter wavelength. A forward voltage was applied to a Schottky diode to control the fine-structure splitting. We observed a decrease and suppression in the fine-structure splitting of the studied single quantum dot with the field, which enabled us to generate polarization-entangled photons with a high fidelity of 0.72 ± 0.05.

Optics and photonics: essential technologies for our nation (technology & engineering)

CERN Document Server

Research, Committee on Harnessing Light: Capitalizing on Optical Science Trends and Challenges for Future; Sciences, Division on Engineering and Physical; Council, National Research

2013-01-01

Optics and photonics technologies are ubiquitous: they are responsible for the displays on smart phones and computing devices, optical fiber that carries the information in the internet, advanced precision manufacturing, enhanced defense capabilities, and a plethora of medical diagnostics tools. The opportunities arising from optics and photonics offer the potential for even greater societal impact in the next few decades, including solar power generation and new efficient lighting that could transform the nation's energy landscape and new optical capabilities that will be essential to support the continued exponential growth of the Internet. As described in the National Research Council report Optics and Photonics: Essential Technologies for our Nation, it is critical for the United States to take advantage of these emerging optical technologies for creating new industries and generating job growth. The report assesses the current state of optical science and engineering in the United States and abroad--incl...

Teleportation of displaced Fock states: Fidelity and their teleported photon number distributions

International Nuclear Information System (INIS)

Quintero, William; Ladera, Celso L

2011-01-01

We consider the teleportation of displaced Fock states which are highly non-classical states of the quantized electromagnetic field which have a set of remarkable quantum properties that include the peculiar oscillations of their photon number distributions. We use the transfer operator formalism to show that the quantum teleportation of a DFS renders a finite superposition of orthonormal DFS's and find its explicit mathematical expression in terms of the compression parameter of the correlated EPR states of the quantum channel. The expression for a teleported Fock state is also derived as a particular case of DFS's teleportation. We finally apply these results to study the fidelity of the teleportation of DFS's and the teleportation of their photon number statistics.

Squeezed State Caused by Inverse of Photon Creation Operator

International Nuclear Information System (INIS)

Xu Xuefen

2006-01-01

Using the photon creation operator's eigenstate theory we derive the normally ordered expansion of inverse of the squeezed creation operator. It turns out that using this operator a kind of excitation on the squeezed vacuum states can be formed.

Quantum optical measurements with undetected photons through vacuum field indistinguishability.

Science.gov (United States)

Lee, Sun Kyung; Yoon, Tai Hyun; Cho, Minhaeng

2017-07-26

Quantum spectroscopy and imaging with undetected idler photons have been demonstrated by measuring one-photon interference between the corresponding entangled signal fields from two spontaneous parametric down conversion (SPDC) crystals. In this Report, we present a new quantum optical measurement scheme utilizing three SPDC crystals in a cascading arrangement; here, neither the detection of the idler photons which interact with materials of interest nor their conjugate signal photons which do not interact with the sample is required. The coherence of signal beams in a single photon W-type path-entangled state is induced and modulated by indistinguishabilities of the idler beams and crucially the quantum vacuum fields. As a result, the optical properties of materials or objects interacting with the idler beam from the first SPDC crystal can be measured by detecting second-order interference between the signal beams generated by the other two SPDC crystals further down the set-up. This gedankenexperiment illustrates the fundamental importance of vacuum fields in generating an optical tripartite entangled state and thus its crucial role in quantum optical measurements.

Manipulation of multi-photon-entanglement. Applications in quantum information processing

International Nuclear Information System (INIS)

Goebel, Alexander Matthias

2008-01-01

Over the last twenty years the field of quantum information processing (QIP) has attracted the attention of many scientists, due to the promise of impressive improvements in the areas of computational speed, communication security and the ability to simulate nature on the micro scale. This thesis describes an experimental work on the physics of multi-photon entanglement and its application in the field of QIP. We have thoroughly developed the necessary techniques to generate multipartite entanglement between up to six photons. By exploiting the developed six-photon interferometer, in this thesis we report for the first time the experimental quantum teleportation of a two-qubit composite system, the realization of multi-stage entanglement swapping, the implementation of a teleportation-based controlled-NOT gate for fault-tolerant quantum computation, the first generation of entanglement in sixpartite photonic graph states and the realization of 'one-way' quantum computation with two-photon four-qubit cluster states. The methods developed in these experiments are of great significance both for exploring the field of QIP and for future experiments on the fundamental tests of quantum mechanics. (orig.)

Photon correlation in single-photon frequency upconversion.

Science.gov (United States)

Gu, Xiaorong; Huang, Kun; Pan, Haifeng; Wu, E; Zeng, Heping

2012-01-30

We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.

Photon-pair generation in nonlinear metal-dielectric one-dimensional photonic structures

Czech Academy of Sciences Publication Activity Database

Javůrek, D.; Svozilík, J.; Peřina ml., Jan

2014-01-01

Roč. 90, č. 5 (2014), "053813-1"-"053813-14" ISSN 1050-2947 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : photon pairs * nonlinear metal-dielectric * one-dimensional photonic structures Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.808, year: 2014

Density of states controls Anderson localization in disordered photonic crystal waveguides

DEFF Research Database (Denmark)

Garcia-Fernández, David; Smolka, Stephan; Stobbe, Søren

2010-01-01

We prove Anderson localization in a disordered photonic crystal waveguide by measuring the ensemble-averaged extinction mean-free path, ℓe, which is controlled by the dispersion in the photon density of states (DOS) of the photonic crystal waveguide. Except for the very low DOS case, where out......-of-plane losses are non-negligible, ℓe can be approximated to be the localization length ξ. The extinction mean-free path shows a fivefold variation between the low- and the high-DOS regime, and it becomes shorter than the sample length thus giving rise to strongly confined modes. The dispersive behavior of ℓe...

Generation efficiency of single-photon current pulses in the Geiger mode of silicon avalanche photodiodes

International Nuclear Information System (INIS)

Verkhovtseva, A. V.; Gergel, V. A.

2009-01-01

Statistical fluctuations of the avalanche's multiplication efficiency were studied as applied to the single-photon (Geiger) mode of avalanche photodiodes. The distribution function of partial multiplication factors with an anomalously wide (of the order of the average) dispersion was obtained. Expressions for partial feedback factors were derived in terms of the average gain and the corresponding dependences on the diode's overvoltage were calculated. Final expressions for the photon-electric pulse's conversion were derived by averaging corresponding formulas over the coordinate of initiating photoelectron generation using the functions of optical photon absorption in silicon.

Precision Controlled Carbon Materials for Next-Generation Optoelectronic and Photonic Devices

Science.gov (United States)

2018-01-08

engineer next-generation carbon-based optoelectronic and photonic devices with superior performance and capabilities. These devices include carbon...electronics; (4) nanostructured graphene plasmonics; and (5) polymer-nanotube conjugate chemistry . (1) Semiconducting carbon nanotube-based...applications (In Preparation, 2018). (5) Polymer-nanotube conjugate chemistry Conjugated polymers can be exploited as agents for selectively wrapping and

Integration of single-photon sources and detectors on GaAs

NARCIS (Netherlands)

Digeronimo, G.E.; Petruzzella, Maurangelo; Birindelli, Simone; Gaudio, Rosalinda; Poor, Sartoon Fattah; van Otten, Frank W.M.; Fiore, Andrea

2016-01-01

Quantum photonic integrated circuits (QPICs) on a GaAs platform allow the generation, manipulation, routing, and detection of non-classical states of light, which could pave the way for quantum information processing based on photons. In this article, the prototype of a multi-functional QPIC is

Exclusive final states from photon-photon collisions at SPEAR

International Nuclear Information System (INIS)

Burke, D.L.

1981-05-01

Studies of exclusive final states produced by the two-photon process have been made at SPEAR by the Mark II and by the Crystal Ball Collaborations. Measurements of π + π - and π 0 π 0 production in the mass region 500 MeV/c 2 2 are presented. These data include strong signals from the well-known f(1270) meson. The A 2 (1310) has been observed via its π 0 eta decay mode and its partial width to γγ has been determined. A measurement of the cross section for the reaction γγ → π + π - π + π - is reported. This channel is found to be small just above the four pion threshold, but exhibits a large enhancement near the rho 0 rho 0 threshold

Teleportation of displaced Fock states: Fidelity and their teleported photon number distributions

Energy Technology Data Exchange (ETDEWEB)

Quintero, William; Ladera, Celso L, E-mail: clladera@usb.ve [Departamento de Fisica, Universidad Simon BolIvar, Apdo. 89000, Caracas 1086 (Venezuela, Bolivarian Republic of)

2011-01-01

We consider the teleportation of displaced Fock states which are highly non-classical states of the quantized electromagnetic field which have a set of remarkable quantum properties that include the peculiar oscillations of their photon number distributions. We use the transfer operator formalism to show that the quantum teleportation of a DFS renders a finite superposition of orthonormal DFS's and find its explicit mathematical expression in terms of the compression parameter of the correlated EPR states of the quantum channel. The expression for a teleported Fock state is also derived as a particular case of DFS's teleportation. We finally apply these results to study the fidelity of the teleportation of DFS's and the teleportation of their photon number statistics.

Application of photonics in next generation telecommunication satellites payloads

Science.gov (United States)

Anzalchi, J.; Inigo, P.; Roy, B.

2017-11-01

Next generation broadband telecommunication satellites are required to provide very high data throughput using complex multibeam architectures. These high throughput `Terabit/s' Satellites will incorporate payloads with very large quantity of conventional RF equipment, co-axial cables, waveguides, harnesses and ancillary equipment, making the Assembly, Integration and Test (AIT) very complex. Use of `RF over Fiber' and associated photonics equipment can make the process of AIT much simpler with the added benefit of significant reduction in number of payload equipment and inherent payload mass.

Unconditionally secure key distillation from multi-photons in a single-photon polarization based quantum key distribution

CERN Document Server

Tamaki, K

2005-01-01

In this presentation, we show some counter-examples to a naive belief that the security of QKD is based on no-cloning theorem. One example is shown by explicitly proving that one can indeed generate an unconditionally secure key from Alice's two-photon emission part in "SARG04 protocol" proposed by V. Scarani et al, in Phys. Rev. Lett. 92, 057901 (2004). This protocol differs from BB84 only in the classical communication. It is, thus, interesting to see how only the classical communication of QKD protocol might qualitatively change its security. We also show that one can generate an unconditionally secure key from the single to the four-photon part in a generalized SARG04 that uses six states. Finally, we also compare the bit error rate threshold of these protocols with the one in BB84 and the original six-state protocol assuming a depolarizing channel.

Conditionally Teleported States Using Optical Squeezers and Photon Counting

Institute of Scientific and Technical Information of China (English)

FAN Hong-Yi; FAN Yue; CHENG Hai-Ling

2002-01-01

By virtue of the neat expression of the two-mode squeezing operator in the Einstein,Podolsky and Rosen entangled state representation,we provide a new approach for discussing the teleportation scheme using optical squeezers and photon counting devices.We derive the explicit form of the teleported states,so that the conditional property of teleportation and teleportation fidelity of this protocol can be scen more clcarly.The derivation is concise.

Diamond-based single-photon emitters

International Nuclear Information System (INIS)

Aharonovich, I; Castelletto, S; Simpson, D A; Su, C-H; Greentree, A D; Prawer, S

2011-01-01

The exploitation of emerging quantum technologies requires efficient fabrication of key building blocks. Sources of single photons are extremely important across many applications as they can serve as vectors for quantum information-thereby allowing long-range (perhaps even global-scale) quantum states to be made and manipulated for tasks such as quantum communication or distributed quantum computation. At the single-emitter level, quantum sources also afford new possibilities in terms of nanoscopy and bio-marking. Color centers in diamond are prominent candidates to generate and manipulate quantum states of light, as they are a photostable solid-state source of single photons at room temperature. In this review, we discuss the state of the art of diamond-based single-photon emitters and highlight their fabrication methodologies. We present the experimental techniques used to characterize the quantum emitters and discuss their photophysical properties. We outline a number of applications including quantum key distribution, bio-marking and sub-diffraction imaging, where diamond-based single emitters are playing a crucial role. We conclude with a discussion of the main challenges and perspectives for employing diamond emitters in quantum information processing.

Optical field-strength polarization of two-mode single-photon states

Energy Technology Data Exchange (ETDEWEB)

Linares, J; Nistal, M C; Barral, D; Moreno, V, E-mail: suso.linares.beiras@usc.e [Optics Area, Department of Applied Physics, Faculty of Physics and School of Optics and Optometry, University of Santiago de Compostela, Campus Universitario Sur s/n, 15782-Santiago de Compostela, Galicia (Spain)

2010-09-15

We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

Optical field-strength polarization of two-mode single-photon states

International Nuclear Information System (INIS)

Linares, J; Nistal, M C; Barral, D; Moreno, V

2010-01-01

We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of the two-mode optical field-strength plane. We will show that the mentioned probability distributions along with the values of quantum Stokes parameters allow us to characterize the polarization of a two-mode single-photon state, in an analogous way to the classical case, and to distinguish conceptually between mixture and partially polarized quantum states; in this way, we propose a simple definition of the quantum polarization degree based on the recent concept of distance measure to an unpolarized distribution, which gives rise to a depolarization degree equivalent to an overlapping between the probability distribution of the quantum state and a non-polarized two-mode Gaussian distribution. The work is particularly intended to university physics teachers and graduate students as well as to physicists and specialists concerned with the issue of optical polarization.

Temporally uncorrelated photon-pair generation by dual-pump four-wave mixing

DEFF Research Database (Denmark)

Christensen, Jesper Bjerge; McKinstrie, C. J.; Rottwitt, Karsten

2016-01-01

We study the preparation of heralded single-photon states using dual-pump spontaneous four-wave mixing. The dual-pump configuration, which in our case employs cross-polarized pumps, allows for a gradual variation of the nonlinear interaction strength enabled by a birefringence-induced walk...

Single-photon sources

International Nuclear Information System (INIS)

Lounis, Brahim; Orrit, Michel

2005-01-01

The concept of the photon, central to Einstein's explanation of the photoelectric effect, is exactly 100 years old. Yet, while photons have been detected individually for more than 50 years, devices producing individual photons on demand have only appeared in the last few years. New concepts for single-photon sources, or 'photon guns', have originated from recent progress in the optical detection, characterization and manipulation of single quantum objects. Single emitters usually deliver photons one at a time. This so-called antibunching of emitted photons can arise from various mechanisms, but ensures that the probability of obtaining two or more photons at the same time remains negligible. We briefly recall basic concepts in quantum optics and discuss potential applications of single-photon states to optical processing of quantum information: cryptography, computing and communication. A photon gun's properties are significantly improved by coupling it to a resonant cavity mode, either in the Purcell or strong-coupling regimes. We briefly recall early production of single photons with atomic beams, and the operation principles of macroscopic parametric sources, which are used in an overwhelming majority of quantum-optical experiments. We then review the photophysical and spectroscopic properties and compare the advantages and weaknesses of various single nanometre-scale objects used as single-photon sources: atoms or ions in the gas phase and, in condensed matter, organic molecules, defect centres, semiconductor nanocrystals and heterostructures. As new generations of sources are developed, coupling to cavities and nano-fabrication techniques lead to improved characteristics, delivery rates and spectral ranges. Judging from the brisk pace of recent progress, we expect single photons to soon proceed from demonstrations to applications and to bring with them the first practical uses of quantum information

Cooperative single-photon subradiant states in a three-dimensional atomic array

Energy Technology Data Exchange (ETDEWEB)

Jen, H.H., E-mail: sappyjen@gmail.com

2016-11-15

We propose a complete superradiant and subradiant states that can be manipulated and prepared in a three-dimensional atomic array. These subradiant states can be realized by absorbing a single photon and imprinting the spatially-dependent phases on the atomic system. We find that the collective decay rates and associated cooperative Lamb shifts are highly dependent on the phases we manage to imprint, and the subradiant state of long lifetime can be found for various lattice spacings and atom numbers. We also investigate both optically thin and thick atomic arrays, which can serve for systematic studies of super- and sub-radiance. Our proposal offers an alternative scheme for quantum memory of light in a three-dimensional array of two-level atoms, which is applicable and potentially advantageous in quantum information processing. - Highlights: • Cooperative single-photon subradiant states in a three-dimensional atomic array. • Subradiant state manipulation via spatially-increasing phase imprinting. • Quantum storage of light in the subradiant state in two-level atoms.

Semiconductor devices for entangled photon pair generation: a review

Science.gov (United States)

Orieux, Adeline; Versteegh, Marijn A. M.; Jöns, Klaus D.; Ducci, Sara

2017-07-01

Entanglement is one of the most fascinating properties of quantum mechanical systems; when two particles are entangled the measurement of the properties of one of the two allows the properties of the other to be instantaneously known, whatever the distance separating them. In parallel with fundamental research on the foundations of quantum mechanics performed on complex experimental set-ups, we assist today with bourgeoning of quantum information technologies bound to exploit entanglement for a large variety of applications such as secure communications, metrology and computation. Among the different physical systems under investigation, those involving photonic components are likely to play a central role and in this context semiconductor materials exhibit a huge potential in terms of integration of several quantum components in miniature chips. In this article we review the recent progress in the development of semiconductor devices emitting entangled photons. We will present the physical processes allowing the generation of entanglement and the tools to characterize it; we will give an overview of major recent results of the last few years and highlight perspectives for future developments.

Distribution of quantum information between an atom and two photons

International Nuclear Information System (INIS)

Weber, Bernhard

2008-01-01

The construction of networks consisting of optically interconnected processing units is a promising way to scale up quantum information processing systems. To store quantum information, single trapped atoms are among the most proven candidates. By placing them in high finesse optical resonators, a bidirectional information exchange between the atoms and photons becomes possible with, in principle, unit efficiency. Such an interface between stationary and ying qubits constitutes a possible node of a future quantum network. The results presented in this thesis demonstrate the prospects of a quantum interface consisting of a single atom trapped within the mode of a high-finesse optical cavity. In a two-step process, we distribute entanglement between the stored atom and two subsequently emitted single photons. The long atom trapping times achieved in the system together with the high photon collection efficiency of the cavity make the applied protocol in principle deterministic, allowing for the creation of an entangled state at the push of a button. Running the protocol on this quasi-stationary quantum interface, the internal state of the atom is entangled with the polarization state of a single emitted photon. The entanglement is generated by driving a vacuum-stimulated Raman adiabatic passage between states of the coupled atom-cavity system. In a second process, the atomic part of the entangled state is mapped onto a second emitted photon using a similar technique and resulting in a polarization-entangled two-photon state. To verify and characterize the photon-photon entanglement, we measured a violation of a Bell inequality and performed a full quantum state tomography. The results prove the prior atom-photon entanglement and demonstrate a quantum information transfer between the atom and the two emitted photons. This reflects the advantages of a high-finesse cavity as a quantum interface in future quantum networks. (orig.)

Distribution of quantum information between an atom and two photons

Energy Technology Data Exchange (ETDEWEB)

Weber, Bernhard

2008-11-03

The construction of networks consisting of optically interconnected processing units is a promising way to scale up quantum information processing systems. To store quantum information, single trapped atoms are among the most proven candidates. By placing them in high finesse optical resonators, a bidirectional information exchange between the atoms and photons becomes possible with, in principle, unit efficiency. Such an interface between stationary and ying qubits constitutes a possible node of a future quantum network. The results presented in this thesis demonstrate the prospects of a quantum interface consisting of a single atom trapped within the mode of a high-finesse optical cavity. In a two-step process, we distribute entanglement between the stored atom and two subsequently emitted single photons. The long atom trapping times achieved in the system together with the high photon collection efficiency of the cavity make the applied protocol in principle deterministic, allowing for the creation of an entangled state at the push of a button. Running the protocol on this quasi-stationary quantum interface, the internal state of the atom is entangled with the polarization state of a single emitted photon. The entanglement is generated by driving a vacuum-stimulated Raman adiabatic passage between states of the coupled atom-cavity system. In a second process, the atomic part of the entangled state is mapped onto a second emitted photon using a similar technique and resulting in a polarization-entangled two-photon state. To verify and characterize the photon-photon entanglement, we measured a violation of a Bell inequality and performed a full quantum state tomography. The results prove the prior atom-photon entanglement and demonstrate a quantum information transfer between the atom and the two emitted photons. This reflects the advantages of a high-finesse cavity as a quantum interface in future quantum networks. (orig.)

Manipulation of multi-photon-entanglement. Applications in quantum information processing

Energy Technology Data Exchange (ETDEWEB)

Goebel, Alexander Matthias

2008-07-16

Over the last twenty years the field of quantum information processing (QIP) has attracted the attention of many scientists, due to the promise of impressive improvements in the areas of computational speed, communication security and the ability to simulate nature on the micro scale. This thesis describes an experimental work on the physics of multi-photon entanglement and its application in the field of QIP. We have thoroughly developed the necessary techniques to generate multipartite entanglement between up to six photons. By exploiting the developed six-photon interferometer, in this thesis we report for the first time the experimental quantum teleportation of a two-qubit composite system, the realization of multi-stage entanglement swapping, the implementation of a teleportation-based controlled-NOT gate for fault-tolerant quantum computation, the first generation of entanglement in sixpartite photonic graph states and the realization of 'one-way' quantum computation with two-photon four-qubit cluster states. The methods developed in these experiments are of great significance both for exploring the field of QIP and for future experiments on the fundamental tests of quantum mechanics. (orig.)

Electron Correlations and Two-Photon States in Polycyclic Aromatic Hydrocarbon Molecules: A Peculiar Role of Geometry

OpenAIRE

Aryanpour, K.; Shukla, A.; Mazumdar, S.

2013-01-01

We present numerical studies of one- and two-photon excited states ordering in a number of polycyclic aromatic hydrocarbon molecules: coronene, hexa-peri-hexabenzocoronene and circumcoronene, all possessing $D_{6h}$ point group symmetry versus ovalene with $D_{2h}$ symmetry, within the Pariser-Parr-Pople model of interacting $\\pi$-electrons. The calculated energies of the two-photon states as well as their relative two-photon absorption cross-sections within the interacting model are qualitat...

Generation and manipulation of entangled photons on silicon chips

Directory of Open Access Journals (Sweden)

Matsuda Nobuyuki

2016-08-01

Full Text Available Integrated quantum photonics is now seen as one of the promising approaches to realize scalable quantum information systems. With optical waveguides based on silicon photonics technologies, we can realize quantum optical circuits with a higher degree of integration than with silica waveguides. In addition, thanks to the large nonlinearity observed in silicon nanophotonic waveguides, we can implement active components such as entangled photon sources on a chip. In this paper, we report recent progress in integrated quantum photonic circuits based on silicon photonics. We review our work on correlated and entangled photon-pair sources on silicon chips, using nanoscale silicon waveguides and silicon photonic crystal waveguides. We also describe an on-chip quantum buffer realized using the slow-light effect in a silicon photonic crystal waveguide. As an approach to combine the merits of different waveguide platforms, a hybrid quantum circuit that integrates a silicon-based photon-pair source and a silica-based arrayed waveguide grating is also presented.

Comparison between photon annihilation-then-creation and photon creation-then-annihilation thermal states: Non-classical and non-Gaussian properties

Science.gov (United States)

Xu, Xue-Xiang; Yuan, Hong-Chun; Wang, Yan

2014-07-01

We investigate the nonclassical properties of arbitrary number photon annihilation-then-creation operation (AC) and creation-then-annihilation operation (CA) to the thermal state (TS), whose normalization factors are related to the polylogarithm function. Then we compare their quantum characters, such as photon number distribution, average photon number, Mandel Q-parameter, purity and the Wigner function. Because of the noncommutativity between the annihilation operator and the creation operator, the ACTS and the CATS have different nonclassical properties. It is found that nonclassical properties are exhibited more strongly after AC than after CA. In addition we also examine their non-Gaussianity. The result shows that the ACTS can present a slightly bigger non-Gaussianity than the CATS.

Comparison between photon annihilation-then-creation and photon creation-then-annihilation thermal states: Non-classical and non-Gaussian properties

International Nuclear Information System (INIS)

Xu Xue-Xiang; Wang Yan; Yuan Hong-Chun

2014-01-01

We investigate the nonclassical properties of arbitrary number photon annihilation-then-creation operation (AC) and creation-then-annihilation operation (CA) to the thermal state (TS), whose normalization factors are related to the polylogarithm function. Then we compare their quantum characters, such as photon number distribution, average photon number, Mandel Q-parameter, purity and the Wigner function. Because of the noncommutativity between the annihilation operator and the creation operator, the ACTS and the CATS have different nonclassical properties. It is found that nonclassical properties are exhibited more strongly after AC than after CA. In addition we also examine their non-Gaussianity. The result shows that the ACTS can present a slightly bigger non-Gaussianity than the CATS. (general)

Mapping the Local Density of Optical States of a Photonic Crystal with Single Quantum Dots

DEFF Research Database (Denmark)

Wang, Qin; Stobbe, Søren; Lodahl, Peter

2011-01-01

We use single self-assembled InGaAs quantum dots as internal probes to map the local density of optical states of photonic crystal membranes. The employed technique separates contributions from nonradiative recombination and spin-flip processes by properly accounting for the role of the exciton...... fine structure. We observe inhibition factors as high as 70 and compare our results to local density of optical states calculations available from the literature, thereby establishing a quantitative understanding of photon emission in photonic crystal membranes. © 2011 American Physical Society....

Deterministic Single-Photon Source for Distributed Quantum Networking

International Nuclear Information System (INIS)

Kuhn, Axel; Hennrich, Markus; Rempe, Gerhard

2002-01-01

A sequence of single photons is emitted on demand from a single three-level atom strongly coupled to a high-finesse optical cavity. The photons are generated by an adiabatically driven stimulated Raman transition between two atomic ground states, with the vacuum field of the cavity stimulating one branch of the transition, and laser pulses deterministically driving the other branch. This process is unitary and therefore intrinsically reversible, which is essential for quantum communication and networking, and the photons should be appropriate for all-optical quantum information processing

'Parity effect' based generation of Schrodinger cat like states in high-Q microcavity

International Nuclear Information System (INIS)

Napoli, A.; Messina, A.

1999-01-01

It has been very recently shown that the dynamics of a two-level atom coupled to a bimodal degenerate cavity field by two-photon processes, is characterized by an interesting nonclassical dynamical behavior christened ''parity effect''. This effect consists in the fact that if the cavity field is prepared leaving one mode in its vacuum state and exciting the other one in a generic linear combination of even number states only, or odd number states only, then there exists an appropriate intensity-dependent interval of time after which the bimodal cavity exhibits macroscopically different parity-dependent quantum features. We show that this nonclassical effect is at the origin of the possibility of generating Schrodinger cat like states of the bimodal field appropriately selecting its initial conditions

Direct detection of a single photon by humans

Science.gov (United States)

Tinsley, Jonathan N.; Molodtsov, Maxim I.; Prevedel, Robert; Wartmann, David; Espigulé-Pons, Jofre; Lauwers, Mattias; Vaziri, Alipasha

2016-01-01

Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds. PMID:27434854

Search for BSM physics in final states with leptons and photons at CMS

CERN Multimedia

CERN. Geneva

2016-01-01

Numerous new physics models predict the existence of heavy resonances decaying to leptons and photons. This talk presents searches for physics beyond the standard model in final states with leptons and photons at CMS, focusing on the recent results obtained using data collected during the 2015 run of the LHC

High-Dimensional Single-Photon Quantum Gates: Concepts and Experiments.

Science.gov (United States)

Babazadeh, Amin; Erhard, Manuel; Wang, Feiran; Malik, Mehul; Nouroozi, Rahman; Krenn, Mario; Zeilinger, Anton

2017-11-03

Transformations on quantum states form a basic building block of every quantum information system. From photonic polarization to two-level atoms, complete sets of quantum gates for a variety of qubit systems are well known. For multilevel quantum systems beyond qubits, the situation is more challenging. The orbital angular momentum modes of photons comprise one such high-dimensional system for which generation and measurement techniques are well studied. However, arbitrary transformations for such quantum states are not known. Here we experimentally demonstrate a four-dimensional generalization of the Pauli X gate and all of its integer powers on single photons carrying orbital angular momentum. Together with the well-known Z gate, this forms the first complete set of high-dimensional quantum gates implemented experimentally. The concept of the X gate is based on independent access to quantum states with different parities and can thus be generalized to other photonic degrees of freedom and potentially also to other quantum systems.

Engineering topological edge states in two dimensional magnetic photonic crystal

Science.gov (United States)

Yang, Bing; Wu, Tong; Zhang, Xiangdong

2017-01-01

Based on a perturbative approach, we propose a simple and efficient method to engineer the topological edge states in two dimensional magnetic photonic crystals. The topological edge states in the microstructures can be constructed and varied by altering the parameters of the microstructure according to the field-energy distributions of the Bloch states at the related Bloch wave vectors. The validity of the proposed method has been demonstrated by exact numerical calculations through three concrete examples. Our method makes the topological edge states "designable."

Temporal interference with frequency-controllable long photons from independent cold atomic sources

Science.gov (United States)

Qian, Peng; Gu, Zhenjie; Wen, Rong; Zhang, Weiping; Chen, J. F.

2018-01-01

The interference of single photons from independent sources is an essential tool in quantum information processing. However, the interfering of photons with long temporal states in a time-resolved manner has rarely been studied. This is because without transmitting spectral filters or coupling to a cavity mode single photons generated in traditional nonlinear crystals suffer from a short temporal profile below 1 ns. With spectral correlation maintained in the biphotons generated from spontaneous four-wave mixing process in cold atom clouds, here we demonstrate the temporal interference of two frequency-tunable long photons from two independent cold atomic sources. We observe and analyze the interference of frequency-mismatched photons, where the phenomenon of the quantum beat at megahertz separation is displayed. Our paper provides more details for the quantum beat of two independent narrow-band single photons, which may find potential application in frequency-encoded photonic qubits in quantum information processing.

Two-photon interference of polarization-entangled photons in a Franson interferometer.

Science.gov (United States)

Kim, Heonoh; Lee, Sang Min; Kwon, Osung; Moon, Han Seb

2017-07-18

We present two-photon interference experiments with polarization-entangled photon pairs in a polarization-based Franson-type interferometer. Although the two photons do not meet at a common beamsplitter, a phase-insensitive Hong-Ou-Mandel type two-photon interference peak and dip fringes are observed, resulting from the two-photon interference effect between two indistinguishable two-photon probability amplitudes leading to a coincidence detection. A spatial quantum beating fringe is also measured for nondegenerate photon pairs in the same interferometer, although the two-photon states have no frequency entanglement. When unentangled polarization-correlated photons are used as an input state, the polarization entanglement is successfully recovered through the interferometer via delayed compensation.

High-Harmonic Generation in Solids with and without Topological Edge States

Science.gov (United States)

Bauer, Dieter; Hansen, Kenneth K.

2018-04-01

High-harmonic generation in the two topological phases of a finite, one-dimensional, periodic structure is investigated using a self-consistent time-dependent density functional theory approach. For harmonic photon energies smaller than the band gap, the harmonic yield is found to differ by up to 14 orders of magnitude for the two topological phases. This giant topological effect is explained by the degree of destructive interference in the harmonic emission of all valence-band (and edge-state) electrons, which strongly depends on whether or not topological edge states are present. The combination of strong-field laser physics with topological condensed matter opens up new possibilities to electronically control strong-field-based light or particle sources or—conversely—to steer by all optical means topological electronics.

On-chip photonic integrated circuit structures for millimeter and terahertz wave signal generation

NARCIS (Netherlands)

Gordón, C.; Guzmán, R. C.; Corral, V.; Carpintero, G.; Leijtens, X.

2015-01-01

We present two different on-chip photonic integrated circuit (PIC) structures for continuous-wave generation of millimeter and terahertz waves, each one using a different approach. One approach is the optical heterodyne method, using an on-chip arrayed waveguide grating laser (OC-AWGL) which is

Toward a New Generation of Photonic Humidity Sensors

Science.gov (United States)

Kolpakov, Stanislav A.; Gordon, Neil T.; Mou, Chengbo; Zhou, Kaiming

2014-01-01

This review offers new perspectives on the subject and highlights an area in need of further research. It includes an analysis of current scientific literature mainly covering the last decade and examines the trends in the development of electronic, acoustic and optical-fiber humidity sensors over this period. The major findings indicate that a new generation of sensor technology based on optical fibers is emerging. The current trends suggest that electronic humidity sensors could soon be replaced by sensors that are based on photonic structures. Recent scientific advances are expected to allow dedicated systems to avoid the relatively high price of interrogation modules that is currently a major disadvantage of fiber-based sensors. PMID:24577524

Two-dimensional 'photon fluid': effective photon-photon interaction and physical realizations

International Nuclear Information System (INIS)

Chiao, R Y; Hansson, T H; Leinaas, J M; Viefers, S

2004-01-01

We describe a recently developed effective theory for atom-mediated photon-photon interactions in a two-dimensional 'photon fluid' confined to a Fabry-Perot resonator. The photons in the lowest longitudinal cavity mode will appear as massive bosons interacting via a renormalized delta-function potential with a strength determined by physical parameters such as the density of atoms and the detuning of the photons relative to the resonance frequency of the atoms. We discuss novel quantum phenomena for photons, such as Bose-Einstein condensation and bound state formation, as well as possible experimental scenarios based on Rydberg atoms in a microwave cavity, or alkali atoms in an optical cavity

Non-Poissonian photon statistics from macroscopic photon cutting materials.

Science.gov (United States)

de Jong, Mathijs; Meijerink, Andries; Rabouw, Freddy T

2017-05-24

In optical materials energy is usually extracted only from the lowest excited state, resulting in fundamental energy-efficiency limits such as the Shockley-Queisser limit for single-junction solar cells. Photon-cutting materials provide a way around such limits by absorbing high-energy photons and 'cutting' them into multiple low-energy excitations that can subsequently be extracted. The occurrence of photon cutting or quantum cutting has been demonstrated in a variety of materials, including semiconductor quantum dots, lanthanides and organic dyes. Here we show that photon cutting results in bunched photon emission on the timescale of the excited-state lifetime, even when observing a macroscopic number of optical centres. Our theoretical derivation matches well with experimental data on NaLaF 4 :Pr 3+ , a material that can cut deep-ultraviolet photons into two visible photons. This signature of photon cutting can be used to identify and characterize new photon-cutting materials unambiguously.

Properties of entangled photon pairs generated in one-dimensional nonlinear photonic-band-gap structures

International Nuclear Information System (INIS)

Perina, Jan Jr.; Centini, Marco; Sibilia, Concita; Bertolotti, Mario; Scalora, Michael

2006-01-01

We have developed a rigorous quantum model of spontaneous parametric down-conversion in a nonlinear 1D photonic-band-gap structure based upon expansion of the field into monochromatic plane waves. The model provides a two-photon amplitude of a created photon pair. The spectra of the signal and idler fields, their intensity profiles in the time domain, as well as the coincidence-count interference pattern in a Hong-Ou-Mandel interferometer are determined both for cw and pulsed pumping regimes in terms of the two-photon amplitude. A broad range of parameters characterizing the emitted down-converted fields can be used. As an example, a structure composed of 49 layers of GaN/AlN is analyzed as a suitable source of photon pairs having high efficiency

Inverse photon-photon processes

International Nuclear Information System (INIS)

Carimalo, C.; Crozon, M.; Kesler, P.; Parisi, J.

1981-12-01

We here consider inverse photon-photon processes, i.e. AB → γγX (where A, B are hadrons, in particular protons or antiprotons), at high energies. As regards the production of a γγ continuum, we show that, under specific conditions the study of such processes might provide some information on the subprocess gg γγ, involving a quark box. It is also suggested to use those processes in order to systematically look for heavy C = + structures (quarkonium states, gluonia, etc.) showing up in the γγ channel. Inverse photon-photon processes might thus become a new and fertile area of investigation in high-energy physics, provided the difficult problem of discriminating between direct photons and indirect ones can be handled in a satisfactory way

Photon Collider Physics with Real Photon Beams

International Nuclear Information System (INIS)

Gronberg, J; Asztalos, S

2005-01-01

Photon-photon interactions have been an important probe into fundamental particle physics. Until recently, the only way to produce photon-photon collisions was parasitically in the collision of charged particles. Recent advances in short-pulse laser technology have made it possible to consider producing high intensity, tightly focused beams of real photons through Compton scattering. A linear e + e - collider could thus be transformed into a photon-photon collider with the addition of high power lasers. In this paper they show that it is possible to make a competitive photon-photon collider experiment using the currently mothballed Stanford Linear Collider. This would produce photon-photon collisions in the GeV energy range which would allow the discovery and study of exotic heavy mesons with spin states of zero and two

Generation of Femtosecond Electron and Photon Pulses

CERN Document Server

Thongbai, Chitrlada; Kangrang, Nopadol; Kusoljariyakul, Keerati; Rhodes, Michael W; Rimjaem, Sakhorn; Saisut, Jatuporn; Vilaithong, Thiraphat; Wichaisirimongkol, Pathom; Wiedemann, Helmut

2005-01-01

Femtosecond electron and photon pulses become a tool of interesting important to study dynamics at molecular or atomic levels. Such short pulses can be generated from a system consisting of an RF-gun with a thermionic cathode, an alpha magnet as a magnetic bunch compressor, and a linear accelerator. The femtosecond electron pulses can be used directly or used as sources to produce electromagnetic radiation of equally short pulses by choosing certain kind of radiation pruduction processes. At the Fast Neutron Research Facility (Thailand), we are especially interested in production of radiation in Far-infrared and X-ray regime. In the far-infrared wavelengths which are longer than the femtosecond pulse length, the radiation is emitted coherently producing intense radiation. In the X-ray regime, development of femtosecond X-ray source is crucial for application in ultrafast science.

NEUTRON AND PHOTON DOSE MAPPING OF A DD NEUTRON GENERATOR.

Science.gov (United States)

Metwally, Walid A; Taqatqa, Osama A; Ballaith, Mohammed M; Chen, Allan X; Piestrup, Melvin A

2017-11-01

Neutron generators are an excellent tool that can be effectively utilized in educational institutions for applications such as neutron activation analysis, neutron radiography, and profiling and irradiation effects. For safety purposes, it is imperative that appropriate measures are taken in order to minimize the radiation dose from such devices to the operators, students and the public. This work presents the simulation and measurement results for the neutron and photon dose rates in the vicinity of the neutron generator installed at the University of Sharjah. A very good agreement is found between the simulated and measured dose rates. All of the public dose constraints were found to be met. The occupational dose constraint was also met after imposing a 200 cm no entry zone around the generator room. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Storage of multiple single-photon pulses emitted from a quantum dot in a solid-state quantum memory

Science.gov (United States)

Tang, Jian-Shun; Zhou, Zong-Quan; Wang, Yi-Tao; Li, Yu-Long; Liu, Xiao; Hua, Yi-Lin; Zou, Yang; Wang, Shuang; He, De-Yong; Chen, Geng; Sun, Yong-Nan; Yu, Ying; Li, Mi-Feng; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Li, Chuan-Feng; Guo, Guang-Can

2015-01-01

Quantum repeaters are critical components for distributing entanglement over long distances in presence of unavoidable optical losses during transmission. Stimulated by the Duan–Lukin–Cirac–Zoller protocol, many improved quantum repeater protocols based on quantum memories have been proposed, which commonly focus on the entanglement-distribution rate. Among these protocols, the elimination of multiple photons (or multiple photon-pairs) and the use of multimode quantum memory are demonstrated to have the ability to greatly improve the entanglement-distribution rate. Here, we demonstrate the storage of deterministic single photons emitted from a quantum dot in a polarization-maintaining solid-state quantum memory; in addition, multi-temporal-mode memory with 1, 20 and 100 narrow single-photon pulses is also demonstrated. Multi-photons are eliminated, and only one photon at most is contained in each pulse. Moreover, the solid-state properties of both sub-systems make this configuration more stable and easier to be scalable. Our work will be helpful in the construction of efficient quantum repeaters based on all-solid-state devices. PMID:26468996

Three-photon laser spectroscopy of even-parity bound states of samarium atom

International Nuclear Information System (INIS)

Gomonaj, O.Yi.; Kudelich, O.Yi.

2002-01-01

The energy spectrum of highly-excited even-parity bound states of a Sm atom, lying in the energy range 34421.1 - 36031.8 cm -1 , is investigated using three-photon resonance-ionization spectroscopy. The energies and total momenta of 48 levels are determined. Eight new levels not observed before are discovered. Thirteen intense two-photon transitions, which can be used in the schemes of Sm atom effective photoionization, are observed

Dual CARS and SHG image acquisition scheme that combines single central fiber and multimode fiber bundle to collect and differentiate backward and forward generated photons

Science.gov (United States)

Weng, Sheng; Chen, Xu; Xu, Xiaoyun; Wong, Kelvin K.; Wong, Stephen T. C.

2016-01-01

In coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) imaging, backward and forward generated photons exhibit different image patterns and thus capture salient intrinsic information of tissues from different perspectives. However, they are often mixed in collection using traditional image acquisition methods and thus are hard to interpret. We developed a multimodal scheme using a single central fiber and multimode fiber bundle to simultaneously collect and differentiate images formed by these two types of photons and evaluated the scheme in an endomicroscopy prototype. The ratio of these photons collected was calculated for the characterization of tissue regions with strong or weak epi-photon generation while different image patterns of these photons at different tissue depths were revealed. This scheme provides a new approach to extract and integrate information captured by backward and forward generated photons in dual CARS/SHG imaging synergistically for biomedical applications. PMID:27375938

Gamma beams generation with high intensity lasers for two photon Breit-Wheeler pair production

Science.gov (United States)

D'Humieres, Emmanuel; Ribeyre, Xavier; Jansen, Oliver; Esnault, Leo; Jequier, Sophie; Dubois, Jean-Luc; Hulin, Sebastien; Tikhonchuk, Vladimir; Arefiev, Alex; Toncian, Toma; Sentoku, Yasuhiko

2017-10-01

Linear Breit-Wheeler pair creation is the lowest threshold process in photon-photon interaction, controlling the energy release in Gamma Ray Bursts and Active Galactic Nuclei, but it has never been directly observed in the laboratory. Using numerical simulations, we demonstrate the possibility to produce collimated gamma beams with high energy conversion efficiency using high intensity lasers and innovative targets. When two of these beams collide at particular angles, our analytical calculations demonstrate a beaming effect easing the detection of the pairs in the laboratory. This effect has been confirmed in photon collision simulations using a recently developed innovative algorithm. An alternative scheme using Bremsstrahlung radiation produced by next generation high repetition rate laser systems is also being explored and the results of first optimization campaigns in this regime will be presented.

Metal-coated semiconductor nanostructures and simulation of photon extraction and coupling to optical fibers for a solid-state single-photon source

International Nuclear Information System (INIS)

Suemune, Ikuo; Nakajima, Hideaki; Liu, Xiangming; Odashima, Satoru; Asano, Tomoya; Iijima, Hitoshi; Huh, Jae-Hoon; Idutsu, Yasuhiro; Sasakura, Hirotaka; Kumano, Hidekazu

2013-01-01

We have realized metal-coated semiconductor nanostructures for a stable and efficient single-photon source (SPS) and demonstrated improved single-photon extraction efficiency by the selection of metals and nanostructures. We demonstrate with finite-difference time-domain (FDTD) simulations that inclination of a pillar sidewall, which changes the structure to a nanocone, is effective in improving the photon extraction efficiency. We demonstrate how such nanocone structures with inclined sidewalls are fabricated with reactive ion etching. With the optimized design, a photon extraction efficiency to outer airside as high as ∼97% generated from a quantum dot in a nanocone structure is simulated, which is the important step in realizing SPS on-demand operations. We have also examined the direct contact of such a metal-embedded nanocone structure with a single-mode fiber facet as a simple and practical method for preparing fiber-coupled SPS and demonstrated practical coupling efficiencies of ∼16% with FDTD simulation. (paper)

Approximate and Conditional Teleportation of an Unknown Atomic State Without Bell-State Measurement with Two-Photon Interaction

Institute of Scientific and Technical Information of China (English)

CHEN Chang-Yong

2006-01-01

A scheme for approximately and conditionally teleporting an unknown atomic state via two-photon interaction in cavity QED is proposed. It is the extension of the scheme of Ref. [11] [Phys. Rev. A 69 (2004) 064302], which is based on Jaynes-Cummings model in QED and where only a time point of system evolution and the corresponding fidelity implementing the teleportation are given. In our scheme, the two-photon interaction Jaynes-Cummings model is used to realize the approximate and conditional teleportation. Our scheme does not involve the Bell-state measurement and an additional atom, only requiring two atoms and one single-mode cavity. The fidelity of the scheme is higher than that of Ref. [11]. The scheme may be generalized to not only the teleportation of the state of a cavity mode to another mode by means of a single atom but also the teleportation of the state of a trapped ion.

High-speed ultra-wideband wireless signals over fiber systems: photonic generation and DSP detection

DEFF Research Database (Denmark)

Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

2009-01-01

We firstly review the efforts in the literature on ultra-wideband (UWB)-over-fiber systems. Secondly, we present experimental results on photonic generation of high-speed UWB signals by both direct modulation and external optical injecting an uncooled semiconductor laser. Furthermore, we introduce...... the use of digital signal processing (DSP) technology to receive the generated UWB signal at 781.25 Mbit/s. Error-free transmission is achieved....

Two photon processes in surface photovoltage spectroscopy

International Nuclear Information System (INIS)

Craig, R.P.; Thurgate, S.M.

1996-01-01

Full text: A significant mid-gap effect has been found in Surface Photovoltage Spectroscopy measurements of cleaved GaAs, InP and Si wafer which is normally interpreted as arising from transitions between surface states and band edges. This large mid-gap effect common to various materials is puzzling as such a high proportion of mid-gap states seems unlikely. Most theories of surface states predict states that tail from the band edges into the gap or states that have a well defined energy in the gap. None propose a large state exactly at E G /2. We recently investigated the variation in SPS spectra with flux density. We find a non-linear correlation in the magnitude of Band-Bending arising from mid-gap and band-gap photon energies. We suggest that the mid-gap feature is due to a two photon absorption process leading to carrier pair generation mediated by mid-gap states in the continuum of band-gap surface states

Study of GMSB models with photon final states using the ATLAS detector

Energy Technology Data Exchange (ETDEWEB)

Terwort, Mark

2009-11-30

Models with gauge mediated supersymmetry breaking (GMSB) provide a possible mechanism to mediate supersymmetry breaking to the electroweak scale. In these models the lightest-supersymmetric particle is the gravitino, while the next-to-lightest supersymmetric particle is either the lightest neutralino or a slepton. In the former case final states with large missing transverse energy from the gravitinos, multiple jets and two hard photons are expected in pp-collisions at the LHC. Depending on the lifetime of the neutralino the photons might not point back to the interaction vertex, which requires dedicated search strategies. Additionally, this feature can be used to measure the neutralino lifetime using either the timing information from the electromagnetic calorimeter or the reconstructed photon direction. Together with the measurements of kinematic endpoints in invariant mass distributions, the lifetime can be used as input for fits of the GMSB model and for the determination of the underlying parameters. The signal selection and the discovery potential for GMSB models with photons in the nal state are discussed using simulated data of the ATLAS detector. In addition, the measurement of supersymmetric particle masses and of the neutralino lifetime as well as the results of the global GMSB fits are presented. (orig.)

Thermo-optically induced interactions in photon Bose-Einstein Condensates

Science.gov (United States)

Alaeian, Hadiseh; Bartels, Clara; Weitz, Martin

Bose-Einstein condensation (BEC), a new state of matter, emerges when the de Broglie wavelength of bosons becomes larger than the particle separation, leading to a macroscopic occupation of the system ground state. Followed by the first experimental demonstrations of BEC in cold atomic gases, this phase transition has been observed in other bosonic gases, as polaritons and phonons. The most recent one, photon BEC, is a promising candidate for a new generation of coherent photon sources. Due to their infancy, however, many of their properties are still unknown or only partly explored. In this talk I will present my latest results on the implications of photon interactions in photon BECs. In particular, I will investigate the effect of a thermo-optic non-linearity, leading to spatially non-local and delayed interactions. Starting from the steady state behavior, I will explore the spectrum of elementary excitations as a small perturbation. Moreover, I will discuss the resulting effective photon dispersion, manifesting various properties including possible superfluidity, as well as roton and maxon modes. The implications of physical parameters as absorption, number of photons in the condensate, and cavity trap on the dispersion will be discussed. The results of this study shed new light on the implication of interactions in photonic many-body systems. Hadiseh Alaeian acknowledges the generous support from Alexander von Humboldt Foundation.

Photonics

CERN Document Server

Andrews, David L

2015-01-01

Discusses the basic physical principles underlying the technology instrumentation of photonics This volume discusses photonics technology and instrumentation. The topics discussed in this volume are: Communication Networks; Data Buffers; Defense and Security Applications; Detectors; Fiber Optics and Amplifiers; Green Photonics; Instrumentation and Metrology; Interferometers; Light-Harvesting Materials; Logic Devices; Optical Communications; Remote Sensing; Solar Energy; Solid-State Lighting; Wavelength Conversion Comprehensive and accessible coverage of the whole of modern photonics Emphas

Nonlocal hyperconcentration on entangled photons using photonic module system

Energy Technology Data Exchange (ETDEWEB)

Cao, Cong; Wang, Tie-Jun; Mi, Si-Chen [School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Zhang, Ru [School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); School of Ethnic Minority Education, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Wang, Chuan, E-mail: wangchuan@bupt.edu.cn [School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

2016-06-15

Entanglement distribution will inevitably be affected by the channel and environment noise. Thus distillation of maximal entanglement nonlocally becomes a crucial goal in quantum information. Here we illustrate that maximal hyperentanglement on nonlocal photons could be distilled using the photonic module and cavity quantum electrodynamics, where the photons are simultaneously entangled in polarization and spatial-mode degrees of freedom. The construction of the photonic module in a photonic band-gap structure is presented, and the operation of the module is utilized to implement the photonic nondestructive parity checks on the two degrees of freedom. We first propose a hyperconcentration protocol using two identical partially hyperentangled initial states with unknown coefficients to distill a maximally hyperentangled state probabilistically, and further propose a protocol by the assistance of an ancillary single photon prepared according to the known coefficients of the initial state. In the two protocols, the total success probability can be improved greatly by introducing the iteration mechanism, and only one of the remote parties is required to perform the parity checks in each round of iteration. Estimates on the system requirements and recent experimental results indicate that our proposal is realizable with existing or near-further technologies.

Nonlocal hyperconcentration on entangled photons using photonic module system

International Nuclear Information System (INIS)

Cao, Cong; Wang, Tie-Jun; Mi, Si-Chen; Zhang, Ru; Wang, Chuan

2016-01-01

Entanglement distribution will inevitably be affected by the channel and environment noise. Thus distillation of maximal entanglement nonlocally becomes a crucial goal in quantum information. Here we illustrate that maximal hyperentanglement on nonlocal photons could be distilled using the photonic module and cavity quantum electrodynamics, where the photons are simultaneously entangled in polarization and spatial-mode degrees of freedom. The construction of the photonic module in a photonic band-gap structure is presented, and the operation of the module is utilized to implement the photonic nondestructive parity checks on the two degrees of freedom. We first propose a hyperconcentration protocol using two identical partially hyperentangled initial states with unknown coefficients to distill a maximally hyperentangled state probabilistically, and further propose a protocol by the assistance of an ancillary single photon prepared according to the known coefficients of the initial state. In the two protocols, the total success probability can be improved greatly by introducing the iteration mechanism, and only one of the remote parties is required to perform the parity checks in each round of iteration. Estimates on the system requirements and recent experimental results indicate that our proposal is realizable with existing or near-further technologies.

Free-Space Quantum Key Distribution with a High Generation Rate KTP Waveguide Photon-Pair Source

Science.gov (United States)

Wilson, J.; Chaffee, D.; Wilson, N.; Lekki, J.; Tokars, R.; Pouch, J.; Lind, A.; Cavin, J.; Helmick, S.; Roberts, T.;

Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in spontaneous parametric down conversion

Science.gov (United States)

Penin, A. N.; Reutova, T. A.; Sergienko, A. V.

1992-01-01

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function.

Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in Spontaneous Parametric Down Conversion

International Nuclear Information System (INIS)

Penin, A.N.; Reutova, T.A.; Sergienko, A.V.

1992-01-01

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function

Tunable microwave signal generation based on an Opto-DMD processor and a photonic crystal fiber

International Nuclear Information System (INIS)

Wang Tao; Sang Xin-Zhu; Yan Bin-Bin; Li Yan; Song Fei-Jun; Zhang Xia; Wang Kui-Ru; Yuan Jin-Hui; Yu Chong-Xiu; Ai Qi; Chen Xiao; Zhang Ying; Chen Gen-Xiang; Xiao Feng; Kamal Alameh

2014-01-01

Frequency-tunable microwave signal generation is proposed and experimentally demonstrated with a dual-wavelength single-longitudinal-mode (SLM) erbium-doped fiber ring laser based on a digital Opto-DMD processor and four-wave mixing (FWM) in a high-nonlinear photonic crystal fiber (PCF). The high-nonlinear PCF is employed for the generation of the FWM to obtain stable and uniform dual-wavelength oscillation. Two different short passive sub-ring cavities in the main ring cavity serve as mode filters to make SLM lasing. The two lasing wavelengths are electronically selected by loading different gratings on the Opto-DMD processor controlled with a computer. The wavelength spacing can be smartly adjusted from 0.165 nm to 1.08 nm within a tuning accuracy of 0.055 nm. Two microwave signals at 17.23 GHz and 27.47 GHz are achieved. The stability of the microwave signal is discussed. The system has the ability to generate a 137.36-GHz photonic millimeter signal at room temperature

Single-photon three-qubit quantum logic using spatial light modulators.

Science.gov (United States)

Kagalwala, Kumel H; Di Giuseppe, Giovanni; Abouraddy, Ayman F; Saleh, Bahaa E A

2017-09-29

The information-carrying capacity of a single photon can be vastly expanded by exploiting its multiple degrees of freedom: spatial, temporal, and polarization. Although multiple qubits can be encoded per photon, to date only two-qubit single-photon quantum operations have been realized. Here, we report an experimental demonstration of three-qubit single-photon, linear, deterministic quantum gates that exploit photon polarization and the two-dimensional spatial-parity-symmetry of the transverse single-photon field. These gates are implemented using a polarization-sensitive spatial light modulator that provides a robust, non-interferometric, versatile platform for implementing controlled unitary gates. Polarization here represents the control qubit for either separable or entangling unitary operations on the two spatial-parity target qubits. Such gates help generate maximally entangled three-qubit Greenberger-Horne-Zeilinger and W states, which is confirmed by tomographical reconstruction of single-photon density matrices. This strategy provides access to a wide range of three-qubit states and operations for use in few-qubit quantum information processing protocols.Photons are essential for quantum information processing, but to date only two-qubit single-photon operations have been realized. Here the authors demonstrate experimentally a three-qubit single-photon linear deterministic quantum gate by exploiting polarization along with spatial-parity symmetry.

F-band millimeter-wave signal generation for wireless link data transmission using on-chip photonic integrated dual-wavelength sources

NARCIS (Netherlands)

Guzman, Robinson; Carpintero, G.; Gordon Gallegos, Carlos; Lawniczuk, Katarzyna; Leijtens, Xaveer

2015-01-01

Millimeter-waves (30-300 GHz) have interest due to the wide bandwidths available for carrying information, enabling broadband wireless communications. Photonics is a key technology for millimeter wave signal generation, recently demonstrating the use of photonic integration to reduce size and cost.

Single-photon ultrashort-lived radionuclides: symposium proceedings

Energy Technology Data Exchange (ETDEWEB)

Paras, P.; Thiessen, J.W. (eds.)

1985-01-01

The purpose was to define the current role and state-of-the-art regarding the development, clinical applications, and usefulness of generator-produced single-photon ultrashort-lived radionuclides (SPUSLR's) and to predict their future impact on medicine. Special emphasis was placed on the generator production of iridium-191, gold-195, and krypton-81. This report contains expanded summaries of the included papers. (ACR)

National Photonics Skills Standard for Technicians.

Science.gov (United States)

Center for Occupational Research and Development, Inc., Waco, TX.

This document defines "photonics" as the generation, manipulation, transport, detection, and use of light information and energy whose quantum unit is the photon. The range of applications of photonics extends from energy generation to detection to communication and information processing. Photonics is at the heart of today's…

A photonic ultra-wideband pulse generator based on relaxation oscillations of a semiconductor laser

DEFF Research Database (Denmark)

Yu, Xianbin; Gibbon, Timothy Braidwood; Pawlik, Michal

2009-01-01

A photonic ultra-wideband (UWB) pulse generator based on relaxation oscillations of a semiconductor laser is proposed and experimentally demonstrated. We numerically simulate the modulation response of a direct modulation laser (DML) and show that due to the relaxation oscillations of the laser......, the generated signals with complex shape in time domain match the Federal Communications Commission (FCC) mask in the frequency domain. Experimental results using a DML agree well with simulation predictions. Furthermore, we also experimentally demonstrate the generation of FCC compliant UWB signals...

Two Photon Decays of Charmonium States Produced in Proton - Anti-proton Annihilations

Energy Technology Data Exchange (ETDEWEB)

Fast, James Elliot [UC, Irvine

1992-01-01

The two photon decays of the $\\eta_c$ and $\\chi_2$ charmonium states have been measured in $p\\bar{p}$ annihilation using the E760 apparatus at Fermilab during the 1990-1991 fixed target run. A search for the $\\eta^\\prime_c$ resonance decaying into two photons has also been conducted. The processes $p\\bar{p} \\to R \\to \\gamma \\gamma$ have been measured using a cooled beam of antiprotons circulating in the Fermilab accumulator ring intersecting an internal hydrogen gas-jet target. The final state photons were measured with a high granularity, high resolution lead glass calorimeter. From a scan of the $\\eta_c$ resonance region, the mass, the total width, and the branching ratio to two photons have been measured. The results are $M_{\\eta_c}$ = 2989.9 ± 2.2 ±0.4 MeV/$c^2$, $\\Gamma_{\\eta_c}$ = 15.6±6.9±6.4 MeV, and $BR({\\eta_c} \\to \\gamma \\gamma)$ = (2.77 ± 1.19 ± 0.43) x $10^{-4}$. Data were taken at the peak of the $X_2$ resonance, and the two photon branching ratio was determined to be $BR(X_2 \\to \\gamma \\gamma)$ = (1.54 ± 0.40 ± 0.24) x $10^{-4}$. Data were collected at several energies around the expected mass of the $\\eta^\\prime_c$. Upper limits have been placed on the product of branching ratios, $BR(\\eta^\\prime_c \\to p\\bar{p})BR(\\eta^\\prime_c \\to \\gamma \\gamma)$, as function of the $\\eta^\\prime_c$ mass and total width.

Multiplexing Superconducting Qubit Circuit for Single Microwave Photon Generation

Science.gov (United States)

George, R. E.; Senior, J.; Saira, O.-P.; Pekola, J. P.; de Graaf, S. E.; Lindström, T.; Pashkin, Yu A.

2017-10-01

We report on a device that integrates eight superconducting transmon qubits in λ /4 superconducting coplanar waveguide resonators fed from a common feedline. Using this multiplexing architecture, each resonator and qubit can be addressed individually, thus reducing the required hardware resources and allowing their individual characterisation by spectroscopic methods. The measured device parameters agree with the designed values, and the resonators and qubits exhibit excellent coherence properties and strong coupling, with the qubit relaxation rate dominated by the Purcell effect when brought in resonance with the resonator. Our analysis shows that the circuit is suitable for generation of single microwave photons on demand with an efficiency exceeding 80%.

Generation and Photonic Guidance of Multi-Octave Optical-Frequency Combs

DEFF Research Database (Denmark)

Couny, F.; Benabid, F.; Roberts, John

2007-01-01

crystal fiber. The waveguidance results not from a photonic band gap but from the inhibited coupling between the core and cladding modes. The spectrum consists of up to 45 high-order Stokes and anti-Stokes lines and is generated by driving the confined gas with a single, moderately powerful (10-kilowatt......) infrared laser, producing 12-nanosecond-duration pulses. This represents a reduction by six orders of magnitude in the required laser powers over previous equivalent techniques and opens up a robust and much simplified route to synthesizing attosecond pulses....

Two Octaves Supercontinuum Generation in Lead-Bismuth Glass Based Photonic Crystal Fiber

Directory of Open Access Journals (Sweden)

Ryszard Buczynski

2014-06-01

Full Text Available In this paper we report a two octave spanning supercontinuum generation in a bandwidth of 700–3000 nm in a single-mode photonic crystal fiber made of lead-bismuth-gallate glass. To our knowledge this is the broadest supercontinuum reported in heavy metal oxide glass based fibers. The fiber was fabricated using an in-house synthesized glass with optimized nonlinear, rheological and transmission properties in the range of 500–4800 nm. The photonic cladding consists of 8 rings of air holes. The fiber has a zero dispersion wavelength (ZDW at 1460 nm. Its dispersion is determined mainly by the first ring of holes in the cladding with a relative hole size of 0.73. Relative hole size of the remaining seven rings is 0.54, which allows single mode performance of the fiber in the infrared range and reduces attenuation of the fundamental mode. The fiber is pumped into anomalous dispersion with 150 fs pulses at 1540 nm. Observed spectrum of 700–3000 nm was generated in 2 cm of fiber with pulse energy below 4 nJ. A flatness of 5 dB was observed in 950–2500 nm range.

Electrically Injected Twin Photon Emitting Lasers at Room Temperature

Directory of Open Access Journals (Sweden)

Claire Autebert

2016-08-01

Full Text Available On-chip generation, manipulation and detection of nonclassical states of light are some of the major issues for quantum information technologies. In this context, the maturity and versatility of semiconductor platforms are important assets towards the realization of ultra-compact devices. In this paper we present our work on the design and study of an electrically injected AlGaAs photon pair source working at room temperature. The device is characterized through its performances as a function of temperature and injected current. Finally we discuss the impact of the device’s properties on the generated quantum state. These results are very promising for the demonstration of electrically injected entangled photon sources at room temperature and let us envision the use of III-V semiconductors for a widespread diffusion of quantum communication technologies.

Generation of sub-Poissonian photon number distribution

DEFF Research Database (Denmark)

Grønbech-Jensen, N.; Ramanujam, P. S.

1990-01-01

An optimization of a nonlinear Mach-Zehnder interferometer to produce sub-Poissonian photon number distribution is proposed. We treat the system quantum mechanically and estimate the mirror parameters, the nonlinearity of the medium in the interferometer, and the input power to obtain minimal...... output uncertainty in the photon number. The power efficiency of the system is shown to be high....

Efficient quantum computing using coherent photon conversion.

Science.gov (United States)

Langford, N K; Ramelow, S; Prevedel, R; Munro, W J; Milburn, G J; Zeilinger, A

2011-10-12

Single photons are excellent quantum information carriers: they were used in the earliest demonstrations of entanglement and in the production of the highest-quality entanglement reported so far. However, current schemes for preparing, processing and measuring them are inefficient. For example, down-conversion provides heralded, but randomly timed, single photons, and linear optics gates are inherently probabilistic. Here we introduce a deterministic process--coherent photon conversion (CPC)--that provides a new way to generate and process complex, multiquanta states for photonic quantum information applications. The technique uses classically pumped nonlinearities to induce coherent oscillations between orthogonal states of multiple quantum excitations. One example of CPC, based on a pumped four-wave-mixing interaction, is shown to yield a single, versatile process that provides a full set of photonic quantum processing tools. This set satisfies the DiVincenzo criteria for a scalable quantum computing architecture, including deterministic multiqubit entanglement gates (based on a novel form of photon-photon interaction), high-quality heralded single- and multiphoton states free from higher-order imperfections, and robust, high-efficiency detection. It can also be used to produce heralded multiphoton entanglement, create optically switchable quantum circuits and implement an improved form of down-conversion with reduced higher-order effects. Such tools are valuable building blocks for many quantum-enabled technologies. Finally, using photonic crystal fibres we experimentally demonstrate quantum correlations arising from a four-colour nonlinear process suitable for CPC and use these measurements to study the feasibility of reaching the deterministic regime with current technology. Our scheme, which is based on interacting bosonic fields, is not restricted to optical systems but could also be implemented in optomechanical, electromechanical and superconducting

Development of all-solid-state flash x-ray generator with photoconductive semiconductor switches

Energy Technology Data Exchange (ETDEWEB)

Xun, Ma; Jianjun, Deng; Hongwei, Liu; Jianqiang, Yuan; Jinfeng, Liu; Bing, Wei; Yanling, Qing; Wenhui, Han; Lingyun, Wang; Pin, Jiang; Hongtao, Li [Key Laboratory of Pulsed Power, Institute of Fluid Physics, CAEP, P.O. Box 919-108, Mianyang 621900 (China)

2014-09-15

A compact, low-jitter, and high repetitive rate all-solid-state flash x-ray generator making use of photo conductive semiconductor switches was developed recently for the diagnostic purpose of some hydrokinetical experiments. The generator consisted of twelve stages of Blumlein pulse forming networks, and an industrial cold cathode diode was used to generate intense x-ray radiations with photon energy up to 220 keV. Test experiments showed that the generator could produce >1 kA electron beam currents and x-ray pulses with ∼40 ns duration under 100 Hz repetitive rates at least (limited by the triggering laser on hand), also found was that the delay time of the cathode explosive emission is crucial to the energy transfer efficiency of the whole system. In addition, factors affecting the diode impedance, how the switching synchronization and diode impedance determining the allowable operation voltage were discussed.

Development of all-solid-state flash x-ray generator with photoconductive semiconductor switches.

Science.gov (United States)

Xun, Ma; Jianjun, Deng; Hongwei, Liu; Jianqiang, Yuan; Jinfeng, Liu; Bing, Wei; Yanling, Qing; Wenhui, Han; Lingyun, Wang; Pin, Jiang; Hongtao, Li

2014-09-01

A compact, low-jitter, and high repetitive rate all-solid-state flash x-ray generator making use of photo conductive semiconductor switches was developed recently for the diagnostic purpose of some hydrokinetical experiments. The generator consisted of twelve stages of Blumlein pulse forming networks, and an industrial cold cathode diode was used to generate intense x-ray radiations with photon energy up to 220 keV. Test experiments showed that the generator could produce >1 kA electron beam currents and x-ray pulses with ~40 ns duration under 100 Hz repetitive rates at least (limited by the triggering laser on hand), also found was that the delay time of the cathode explosive emission is crucial to the energy transfer efficiency of the whole system. In addition, factors affecting the diode impedance, how the switching synchronization and diode impedance determining the allowable operation voltage were discussed.

High-speed ultra-wideband wireless signals over fiber systems: Photonic generation and DSP detection

DEFF Research Database (Denmark)

Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

2009-01-01

We firstly review the efforts in the literature on UWB over-fiber systems. Secondly, we present experimental results on photonic generation of high-speed UWB signals by both direct modulation and external optical injecting an uncooled semiconductor laser. Furthermore, we introduce the use of digi...

Polarised two-photon excitation of quantum well excitons for manipulation of optically pumped terahertz lasers

Energy Technology Data Exchange (ETDEWEB)

Slavcheva, G., E-mail: gsk23@bath.ac.uk [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Kavokin, A.V., E-mail: A.Kavokin@soton.ac.uk [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Spin Optics Laboratory, St. Petersburg State University, 1, Ulyanovskaya 198504 (Russian Federation)

2014-11-15

Optical pumping of excited exciton states in a semiconductor quantum well embedded in a microcavity is a tool for realisation of ultra-compact terahertz (THz) lasers based on stimulated optical transition between excited (2p) and ground (1s) exciton state. We show that the probability of two-photon absorption by a 2p-exciton is strongly dependent on the polarisation of both pumping photons. Five-fold variation of the threshold power for terahertz lasing by switching from circular to co-linear pumping is predicted. We identify photon polarisation configurations for achieving maximum THz photon generation quantum efficiency.

Heralded creation of photonic qudits from parametric down-conversion using linear optics

Science.gov (United States)

Yoshikawa, Jun-ichi; Bergmann, Marcel; van Loock, Peter; Fuwa, Maria; Okada, Masanori; Takase, Kan; Toyama, Takeshi; Makino, Kenzo; Takeda, Shuntaro; Furusawa, Akira

2018-05-01

We propose an experimental scheme to generate, in a heralded fashion, arbitrary quantum superpositions of two-mode optical states with a fixed total photon number n based on weakly squeezed two-mode squeezed state resources (obtained via weak parametric down-conversion), linear optics, and photon detection. Arbitrary d -level (qudit) states can be created this way where d =n +1 . Furthermore, we experimentally demonstrate our scheme for n =2 . The resulting qutrit states are characterized via optical homodyne tomography. We also discuss possible extensions to more than two modes concluding that, in general, our approach ceases to work in this case. For illustration and with regards to possible applications, we explicitly calculate a few examples such as NOON states and logical qubit states for quantum error correction. In particular, our approach enables one to construct bosonic qubit error-correction codes against amplitude damping (photon loss) with a typical suppression of √{n }-1 losses and spanned by two logical codewords that each correspond to an n -photon superposition for two bosonic modes.

Discrimination of optical coherent states using a photon number resolving detector

DEFF Research Database (Denmark)

Wittmann, C.; Andersen, Ulrik Lund; Leuchs, G.

2010-01-01

The discrimination of non-orthogonal quantum states with reduced or without errors is a fundamental task in quantum measurement theory. In this work, we investigate a quantum measurement strategy capable of discriminating two coherent states probabilistically with significantly smaller error...... probabilities than can be obtained using non-probabilistic state discrimination. We find that appropriate postselection of the measurement data of a photon number resolving detector can be used to discriminate two coherent states with small error probability. We compare our new receiver to an optimal...

Quantum random number generator

Science.gov (United States)

Pooser, Raphael C.

2016-05-10

A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

A comparison of electrical and photonic pulse generation for IR-UWB on fiber links

DEFF Research Database (Denmark)

Rodes Lopez, Roberto; Caballero Jambrina, Antonio; Yu, Xianbin

2010-01-01

We present and compare experimental results for electrical and photonic generation of 2-Gb/s pulses for impulse radio ultra-wideband on fiber transmission systems based on direct current modulation of a semiconductor laser diode and external optical injection of a semiconductor laser diode......, respectively. We assess the performance of the two generation approaches in terms of bit-error rate after propagation over 20 km of optical fiber followed by wireless transmission....

Spin-photon interface and spin-controlled photon switching in a nanobeam waveguide

DEFF Research Database (Denmark)

Javadi, Alisa; Ding, Dapeng; Appel, Martin Hayhurst

2018-01-01

Access to the electron spin is at the heart of many protocols for integrated and distributed quantum-information processing [1-4]. For instance, interfacing the spin-state of an electron and a photon can be utilized to perform quantum gates between photons [2,5] or to entangle remote spin states [6......-9]. Ultimately, a quantum network of entangled spins constitutes a new paradigm in quantum optics [1]. Towards this goal, an integrated spin-photon interface would be a major leap forward. Here we demonstrate an efficient and optically programmable interface between the spin of an electron in a quantum dot...... and photons in a nanophotonic waveguide. The spin can be deterministically prepared with a fidelity of 96\\%. Subsequently the system is used to implement a "single-spin photonic switch", where the spin state of the electron directs the flow of photons through the waveguide. The spin-photon interface may...

Optical Field-Strength Polarization of Two-Mode Single-Photon States

Science.gov (United States)

Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

2010-01-01

We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses generated in a gas-filled hollow-core photonic crystal fiber

Science.gov (United States)

Bromberger, H.; Ermolov, A.; Belli, F.; Liu, H.; Calegari, F.; Chávez-Cervantes, M.; Li, M. T.; Lin, C. T.; Abdolvand, A.; Russell, P. St. J.; Cavalleri, A.; Travers, J. C.; Gierz, I.

2015-08-01

A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few μJ energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi2Se3 with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude gain in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with photon energies that cover the first Brillouin zone of most materials.

Density of states calculations and multiple-scattering theory for photons

International Nuclear Information System (INIS)

Moroz, A.

1994-05-01

The density of states for a finite or an infinite cluster of scatterers in the case of both, electrons and photons, can be represented in a general form as the sum over all Krein-Friedel contributions of individual scatterers and a contribution due to the presence of multiple scatterers. The latter is given by the sum over all periodic orbits between different scatterers. General three dimensional multiple-scattering theory for electromagnetic waves in the presence of scatterers of arbitrary shape is presented. Vector structure constants are calculated and general rules for obtaining them from known scalar structure constants are given. The KKR equations for photons are explicitly written down. (author). 22 refs., 2 figs

A photon position sensor consisting of single-electron circuits

International Nuclear Information System (INIS)

Kikombo, Andrew Kilinga; Amemiya, Yoshihito; Tabe, Michiharu

2009-01-01

This paper proposes a solid-state sensor that can detect the position of incident photons with a high spatial resolution. The sensor consists of a two-dimensional array of single-electron oscillators, each coupled to its neighbors through coupling capacitors. An incident photon triggers an excitatory circular wave of electron tunneling in the oscillator array. The wave propagates in all directions to reach the periphery of the array. By measuring the arrival time of the wave at the periphery, we can know the position of the incident photon. The tunneling wave's generation, propagation, arrival at the array periphery, and the determination of incident photon positions are demonstrated with the results of Monte Carlo based computer simulations.

Bio-Inspired Photon Absorption and Energy Transfer for Next Generation Photovoltaic Devices

Science.gov (United States)

Magsi, Komal

Nature's solar energy harvesting system, photosynthesis, serves as a model for photon absorption, spectra broadening, and energy transfer. Photosynthesis harvests light far differently than photovoltaic cells. These differences offer both engineering opportunity and scientific challenges since not all of the natural photon absorption mechanisms have been understood. In return, solar cells can be a very sensitive probe for the absorption characteristics of molecules capable of transferring charge to a conductive interface. The objective of this scientific work is the advancement of next generation photovoltaics through the development and application of natural photo-energy transfer processes. Two scientific methods were used in the development and application of enhancing photon absorption and transfer. First, a detailed analysis of photovoltaic front surface fluorescent spectral modification and light scattering by hetero-structure was conducted. Phosphor based spectral down-conversion is a well-known laser technology. The theoretical calculations presented here indicate that parasitic losses and light scattering within the spectral range are large enough to offset any expected gains. The second approach for enhancing photon absorption is based on bio-inspired mechanisms. Key to the utilization of these natural processes is the development of a detailed scientific understanding and the application of these processes to cost effective systems and devices. In this work both aspects are investigated. Dye type solar cells were prepared and tested as a function of Chlorophyll (or Sodium-Copper Chlorophyllin) and accessory dyes. Forster has shown that the fluorescence ratio of Chlorophyll is modified and broadened by separate photon absorption (sensitized absorption) through interaction with nearby accessory pigments. This work used the dye type solar cell as a diagnostic tool by which to investigate photon absorption and photon energy transfer. These experiments shed

Packaged semiconductor laser optical phase locked loop for photonic generation, processing and transmission of microwave signals

DEFF Research Database (Denmark)

Langley, L.N.; Elkin, M.D.; Edege, C.

1999-01-01

In this paper, we present the first fully packaged semiconductor laser optical phase-locked loop (OPLL) microwave photonic transmitter. The transmitter is based on semiconductor lasers that are directly phase locked without the use of any other phase noise-reduction mechanisms. In this transmitter......, the lasers have a free-running summed linewidth of 6 MHz and the OPLL has a feedback bandwidth of 70 MHz, A state-of-the-art performance is obtained, with a total phase-error variance of 0.05 rad(2) (1-GHz bandwidth) and a carrier phase-error variance of 7x10(-4) rad(2) in a 15-MHz bandwidth. Carriers...... are generated in the range of 7-14 GHz. The OPLL transmitter has been fully packaged for practical use in field trials. This is the first time this type of transmitter has been fabricated in a packaged state which is a significant advance on the route to practical application....

Quasi-B-mode generated by high-frequency gravitational waves and corresponding perturbative photon fluxes

Energy Technology Data Exchange (ETDEWEB)

Li, Fangyu, E-mail: cqufangyuli@hotmail.com [Institute of Gravitational Physics, Department of Physics, Chongqing University, Chongqing 400044 (China); Wen, Hao [Institute of Gravitational Physics, Department of Physics, Chongqing University, Chongqing 400044 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Fang, Zhenyun [Institute of Gravitational Physics, Department of Physics, Chongqing University, Chongqing 400044 (China); Wei, Lianfu; Wang, Yiwen; Zhang, Miao [Quantum Optoelectronics Laboratory, Southwest Jiaotong University, Chengdu 610031 (China)

2016-10-15

Interaction of very low-frequency primordial (relic) gravitational waves (GWs) to cosmic microwave background (CMB) can generate B-mode polarization. Here, for the first time we point out that the electromagnetic (EM) response to high-frequency GWs (HFGWs) would produce quasi-B-mode distribution of the perturbative photon fluxes. We study the duality and high complementarity between such two B-modes, and it is shown that such two effects are from the same physical origin: the tensor perturbation of the GWs and not the density perturbation. Based on this quasi-B-mode in HFGWs and related numerical calculation, it is shown that the distinguishing and observing of HFGWs from the braneworld would be quite possible due to their large amplitude, higher frequency and very different physical behaviors between the perturbative photon fluxes and background photons, and the measurement of relic HFGWs may also be possible though face to enormous challenge.

Single-Shot Quantum Nondemolition Detection of Individual Itinerant Microwave Photons

Science.gov (United States)

Besse, Jean-Claude; Gasparinetti, Simone; Collodo, Michele C.; Walter, Theo; Kurpiers, Philipp; Pechal, Marek; Eichler, Christopher; Wallraff, Andreas

2018-04-01

Single-photon detection is an essential component in many experiments in quantum optics, but it remains challenging in the microwave domain. We realize a quantum nondemolition detector for propagating microwave photons and characterize its performance using a single-photon source. To this aim, we implement a cavity-assisted conditional phase gate between the incoming photon and a superconducting artificial atom. By reading out the state of this atom in a single shot, we reach an external (internal) photon-detection fidelity of 50% (71%), limited by transmission efficiency between the source and the detector (75%) and the coherence properties of the qubit. By characterizing the coherence and average number of photons in the field reflected off the detector, we demonstrate its quantum nondemolition nature. We envisage applications in generating heralded remote entanglement between qubits and for realizing logic gates between propagating microwave photons.

Ab Initio Optimized Effective Potentials for Real Molecules in Optical Cavities: Photon Contributions to the Molecular Ground State

Science.gov (United States)

2018-01-01

We introduce a simple scheme to efficiently compute photon exchange-correlation contributions due to the coupling to transversal photons as formulated in the newly developed quantum-electrodynamical density-functional theory (QEDFT).1−5 Our construction employs the optimized-effective potential (OEP) approach by means of the Sternheimer equation to avoid the explicit calculation of unoccupied states. We demonstrate the efficiency of the scheme by applying it to an exactly solvable GaAs quantum ring model system, a single azulene molecule, and chains of sodium dimers, all located in optical cavities and described in full real space. While the first example is a two-dimensional system and allows to benchmark the employed approximations, the latter two examples demonstrate that the correlated electron-photon interaction appreciably distorts the ground-state electronic structure of a real molecule. By using this scheme, we not only construct typical electronic observables, such as the electronic ground-state density, but also illustrate how photon observables, such as the photon number, and mixed electron-photon observables, for example, electron–photon correlation functions, become accessible in a density-functional theory (DFT) framework. This work constitutes the first three-dimensional ab initio calculation within the new QEDFT formalism and thus opens up a new computational route for the ab initio study of correlated electron–photon systems in quantum cavities. PMID:29594185

Extension of supercontinuum spectrum generated in photonic crystal fiber by using chirped femtosecond pulses

Science.gov (United States)

Vengelis, Julius; Jarutis, Vygandas; Sirutkaitis, Valdas

2017-08-01

We present results of experimental and numerical investigation of supercontinuum generation in polarization maintaining photonic crystal fiber (PCF) using chirped femtosecond pulses. The initial unchirped pump pulse source was a mode-locked Yb:KGW laser generating 52 nJ energy 110 fs duration pulses at 1030 nm with 76 MHz repetition rate. The nonlinear medium was a 32 cm long polarization maintaining PCF manufactured by NKT Photonics A/S. We demonstrated the influence of pump pulse chirp on spectral characteristics of supercontinuum. We showed that by chirping pump pulses positively or negatively one can obtain broader supercontinuum spectrum than in case of unchirped pump pulses at the same peak power. Moreover, the extension can be controlled by changing the amount of pump pulse chirp. In our case the supercontinuum spectrum width was extended by up to 115 nm (at maximum chirp value of +10500 fs2 that we could achieve in our setup) compared to the case of unchirped pump at the same peak power.

One-way quantum computation via manipulation of polarization and momentum qubits in two-photon cluster states

International Nuclear Information System (INIS)

Vallone, G; Pomarico, E; De Martini, F; Mataloni, P

2008-01-01

Four-qubit cluster states of two photons entangled in polarization and linear momentum have been used to realize a complete set of single qubit rotations and the C-NOT gate for equatorial qubits with high values of fidelity. By the computational equivalence of the two degrees of freedom our result demonstrate the suitability of two photon cluster states for rapid and efficient one-way quantum computing

Higher-order nonclassical effects generated by multiple-photon annihilation-then-creation and creation-then-annihilation coherent states

International Nuclear Information System (INIS)

Yuan Hong-Chun; Xiao Jin; Xiong Chao; Zhu Xi-Fang; Xu Xue-Xiang

2016-01-01

We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilation-then-creation (AC) and creation-then-annihilation (CA) on the coherent state, respectively, such as higher-order sub-Poissonian statistics and higher-order squeezing-enhanced effect. The corresponding analytical expressions are derived in detail depending on m . By numerically comparing those quantum properties, it is found that these states above have very different nonclassical properties and nonclassicality is exhibited more strongly after AC operation than after CA operation. (paper)

Nonclassical-light generation in a photonic-band-gap nonlinear planar waveguide

International Nuclear Information System (INIS)

Perina, Jan Jr.; Sibilia, Concita; Tricca, Daniela; Bertolotti, Mario

2004-01-01

The optical parametric process occurring in a photonic-band-gap planar waveguide is studied from the point of view of nonclassical-light generation. The nonlinearly interacting optical fields are described by the generalized superposition of coherent signals and noise using the method of operator linear corrections to a classical strong solution. Scattered backward-propagating fields are taken into account. Squeezed light as well as light with sub-Poissonian statistics can be obtained in two-mode fields under the specified conditions

Constraining nuclear photon strength functions by the decay properties of photo-excited states

Science.gov (United States)

Isaak, J.; Savran, D.; Krtička, M.; Ahmed, M. W.; Beller, J.; Fiori, E.; Glorius, J.; Kelley, J. H.; Löher, B.; Pietralla, N.; Romig, C.; Rusev, G.; Scheck, M.; Schnorrenberger, L.; Silva, J.; Sonnabend, K.; Tonchev, A. P.; Tornow, W.; Weller, H. R.; Zweidinger, M.

2013-12-01

A new approach for constraining the low-energy part of the electric dipole Photon Strength Function (E1-PSF) is presented. Experiments at the Darmstadt High-Intensity Photon Setup and the High Intensity γ→-Ray Source have been performed to investigate the decay properties of 130Te between 5.50 and 8.15 MeV excitation energy. In particular, the average γ-ray branching ratio to the ground state and the population intensity of low-lying excited states have been studied. A comparison to the statistical model shows that the latter is sensitive to the low-energy behavior of the E1-PSF, while the average ground state branching ratio cannot be described by the statistical model in the energy range between 5.5 and 6.5 MeV.

Nonperturbative aspects of the quark-photon vertex

International Nuclear Information System (INIS)

Frank, M.R.

1994-01-01

The electromagnetic interaction with quarks is investigated through a relativistic, electromagnetic gauge-invariant treatment. Gluon dressing of the quark-photon vertex and the quark self-energy functions is described by the inhomogeneous Bethe-Salpeter equation in the ladder approximation and the Schwinger-Dyson equation in the rainbow approximation respectively. Results for the calculation of the quark-photon vertex are presented in both the time-like and space-like regions of photon momentum squared, however emphasis is placed on the space-like region relevant to electron scattering. The treatment presented here simultaneously addresses the role of dynamically generated q bar q vector bound states and the approach to asymptotic behavior. The resulting description is therefore applicable over the entire range of momentum transfers available in electron scattering experiments. Input parameters are limited to the model gluon two-point function which is chosen to reflect confinement and asymptotic freedom and are largely constrained by the obtained bound-state spectrum

Single-photon detector operating under extremely high background photon flux conditions

International Nuclear Information System (INIS)

Prochazka, Ivan; Sopko, Bruno; Blazej, Josef

2009-01-01

We are reporting our results in research and development in the field of avalanche semiconductor single-photon detectors and their application. Our goal was a development of a solid-state photon-counting detector capable of high-precision photon arrival time tagging in extremely harsh operating conditions. The background photon flux exceeding 10 9 photons per second hitting the detector active area should not avoid the useful signal detection and recognition on the signal level of units of photons per second. This is background photon flux about two orders of magnitude higher than what the conventional solid-state photon counters accept. The detection timing resolution should be better than 100 ps and the delay stability should be on picosecond level. We have developed and tested the active quenched and gated avalanche structure on silicon providing the required features in connection with the K14 detection chips. The detector is capable of gated operation under the conditions of background photon flux of 5x10 9 photons per second. The operational detector tolerates long term exposures to the input photon flux exceeding 10 15 photons (>1 mW) per second without damage.

Theory of even-parity states and two-photon spectra of conjugated polymers

Science.gov (United States)

McWilliams, P. C. M.; Hayden, G. W.; Soos, Z. G.

1991-04-01

The two-photon absorption (TPA) spectrum of interacting π electrons in conjugated polymers is shown to be qualitatively different from any single-particle description, including the Hartree-Fock limit. Alternating transfer integrals t(1+/-δ) along the backbone lead to a weak TPA below the one-photon gap Eg for arbitrarily weak correlations at δ=0, for intermediate correlations at δ=0.07 in polyenes, and for strong correlations at any δtheory to Eg in the limit of strong correlations in Hubbard models and is around 1.5Eg for Pariser-Parr-Pople (PPP) parameters. The PPP model, which accounts for one- and two-photon excitations of finite polyenes, is extended to even-parity states in polydiacetylenes (PDA's), polyacetylene (PA), and polysilanes (PS's). Previous experimental data for PDA and PS support both the strong TPA above Eg and weak TPA slightly below Eg for δ=0.15 in PDA and above Eg for δ~0.3 in PS. The strong TPA expected around 1.5Eg in isolated PA strands shifts to ~Eg due to interchain π-electron dispersion forces. TPA intensities in correlated states are shown to reflect both ionicity and mean-square charge separation. The even-parity states of conjugated polymers, like those of polyenes, show qualitatively different features associated with electron-electron correlations.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul

Science.gov (United States)

Alavi, S. E.; Soltanian, M. R. K.; Amiri, I. S.; Khalily, M.; Supa'At, A. S. M.; Ahmad, H.

2016-01-01

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul.

Science.gov (United States)

Alavi, S E; Soltanian, M R K; Amiri, I S; Khalily, M; Supa'at, A S M; Ahmad, H

2016-01-27

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated.

Integration of Single-Photon Sources and Detectors on GaAs

Directory of Open Access Journals (Sweden)

Giulia Enrica Digeronimo

2016-10-01

Full Text Available Quantum photonic integrated circuits (QPICs on a GaAs platform allow the generation, manipulation, routing, and detection of non-classical states of light, which could pave the way for quantum information processing based on photons. In this article, the prototype of a multi-functional QPIC is presented together with our recent achievements in terms of nanofabrication and integration of each component of the circuit. Photons are generated by excited InAs quantum dots (QDs and routed through ridge waveguides towards photonic crystal cavities acting as filters. The filters with a transmission of 20% and free spectral range ≥66 nm are able to select a single excitonic line out of the complex emission spectra of the QDs. The QD luminescence can be measured by on-chip superconducting single photon detectors made of niobium nitride (NbN nanowires patterned on top of a suspended nanobeam, reaching a device quantum efficiency up to 28%. Moreover, two electrically independent detectors are integrated on top of the same nanobeam, resulting in a very compact autocorrelator for on-chip g(2(τ measurements.

EPR experiment and 2-photon interferometry: Report of a 2-photon interference experiment

International Nuclear Information System (INIS)

Shih, Y.H.; Rubin, M.H.; Sergienko, A.V.

1992-01-01

After a very brief review of the historical Einstein, Podolsky, and Rosen (EPR) experiments, a new two-photon interference type EPR experiment is reported. A two-photon state was generated by optical parametric down conversion. Pairs of light quanta with degenerate frequency but divergent directions of propagation were sent to two independent Michelson interferometers. First and second order interference effectors were studied. Different than other reports, we observed that the second order interference visibility vanished when the optical path difference of the interferometers were much less than the coherence length of the pumping laser beam. However, we also observed that the second order interference behaved differently depending on whether the interferometers were set at equal or different optical path differences

EPR experiment and 2-photon interferometry: Report of a 2-photon interference experiment

Science.gov (United States)

Shih, Y. H.; Rubin, M. H.; Sergienko, A. V.

1992-01-01

After a very brief review of the historical Einstein, Podolsky, and Rosen (EPR) experiments, a new two-photon interference type EPR experiment is reported. A two-photon state was generated by optical parametric down conversion. Pairs of light quanta with degenerate frequency but divergent directions of propagation were sent to two independent Michelson interferometers. First and second order interference effectors were studied. Different than other reports, we observed that the second order interference visibility vanished when the optical path difference of the interferometers were much less than the coherence length of the pumping laser beam. However, we also observed that the second order interference behaved differently depending on whether the interferometers were set at equal or different optical path differences.

Interaction of VUV-photons with molecules. Spectroscopy and dynamics of molecular superexcited states

International Nuclear Information System (INIS)

Hatano, Y.

2002-01-01

Complete text of publication follows. A survey is given of recent progress in experimental studies of the interaction of VUV-photons with molecules, i.e., those of photoabsorption, photoionization, and photodissociation of molecules in the excitation photon energy range of 10-50 eV, with a particular emphasis placed on current understanding of the spectroscopy and dynamics of formed molecular superexcited states. These studies are of great importance in understanding the interaction of ionizing radiation with matter. Molecules studied are ranged from simple diatomic and triatomic molecules to polyatomic molecules such as hydrocarbons. Most of the observed molecular superexcited states are assigned to high Rydber states which are vibrationally, doubly, or inner-core excited and converge to each of ion states. Non-Rydberg superexcited states are also observed. Dissociation into neutral fragments in comparison with ionization is of unexpectedly great importance in the observed decay of each of these state-assigned superexcited molecules. Dissociation dynamics as well as its products of superexcited states are remarkably different from those of lower excited states below about ionization thresholds. Some remarks are also presented of molecules in the condensed phase

Experimental entanglement and nonlocality of a two-photon six-qubit cluster state.

Science.gov (United States)

Ceccarelli, Raino; Vallone, Giuseppe; De Martini, Francesco; Mataloni, Paolo; Cabello, Adán

2009-10-16

We create a six-qubit linear cluster state by transforming a two-photon hyperentangled state in which three qubits are encoded in each particle, one in the polarization and two in the linear momentum degrees of freedom. For this state, we demonstrate genuine six-qubit entanglement, persistency of entanglement against the loss of qubits, and higher violation than in previous experiments on Bell inequalities of the Mermin type.

On bound states of photons in noncommutative U(1) gauge theory

International Nuclear Information System (INIS)

Fatollahi, A.H.; Jafari, A.

2006-01-01

We consider the possibility that photons of noncommutative U(1) gauge theory can make bound states. Using the potential model, developed based on the constituent gluon picture of QCD glue-balls, arguments are presented in favor of the existence of these bound states. The basic ingredient of the potential model is that the self-interacting massless gauge particles may get mass by the inclusion of non-perturbative effects. (orig.)

The absorbed dose in air of photons generated from secondary cosmic rays at sea level at Nagoya, Japan

International Nuclear Information System (INIS)

Akhmad, Y.R.

1995-01-01

Investigations have been carried out to determine the absorbed dose in air of photons generated from secondary cosmic radiation at sea level at Nagoya, Japan. To isolate the contribution from cosmic photons, the pulse-height distributions due to μ particles and electrons were eliminated from the observed pulse-height distribution of a measurement with a 3'' diam. spherical NaI(Tl) detector. The pulse height due to μ particles and electrons was inferred from the coincidence technique using two types of scintillation detectors with different sensitivities to photons. To obtain the photon fluence rate for further dose calculation, the pulse-height distribution of cosmic photons was unfolded by the iterative method. The mean and its standard deviation of the absorbed dose in air and fluence rate due to cosmic photons calculated from a one year observation are 2.86±0.05 nGy.h -1 and 0.1342±0.0015 photons.cm -2 .s -1 , respectively. The absorbed dose in air from cosmic photons was 0.5% lower during autumn to winter and 0.6% higher during spring to summer than the mean taken over the year. (author)

Quasi-B-mode generated by high-frequency gravitational waves and corresponding perturbative photon fluxes

Directory of Open Access Journals (Sweden)

F.Y. Fangyu Li

2016-10-01

Full Text Available Interaction of very low-frequency primordial (relic gravitational waves (GWs to cosmic microwave background (CMB can generate B-mode polarization. Here, for the first time we point out that the electromagnetic (EM response to high-frequency GWs (HFGWs would produce quasi-B-mode distribution of the perturbative photon fluxes. We study the duality and high complementarity between such two B-modes, and it is shown that such two effects are from the same physical origin: the tensor perturbation of the GWs and not the density perturbation. Based on this quasi-B-mode in HFGWs and related numerical calculation, it is shown that the distinguishing and observing of HFGWs from the braneworld would be quite possible due to their large amplitude, higher frequency and very different physical behaviors between the perturbative photon fluxes and background photons, and the measurement of relic HFGWs may also be possible though face to enormous challenge.

Deterministic Generation of Quantum State Transfer Between Spatially Separated Single Molecule Magnets

International Nuclear Information System (INIS)

Song Peijun; Lue Xinyou; Huang Pei; Hao Xiangying; Yang Xiaoxue

2010-01-01

We propose a new scheme for realizing deterministic quantum state transfer (QST) between two spatially separated single molecule magnets (SMMs) with the framework of cavity quantum electrodynamics (QED). In the present scheme, two SMMs are trapped in two spatially separated optical cavities coupled by an optical fiber. Through strictly numerically simulating, we demonstrate that our scheme is robust with respect to the SMMs' spontaneous decay and fiber loss under the conditions of dispersive SMMs-field interaction and strong coupling of cavity fiber. In addition, we also discuss the influence of photon leakage out of cavities and show that our proposal is good enough to demonstrate the generation of QST with high fidelity utilizing the current experimental technology. The present investigation provides research opportunities for realizing QST between solid-state qubits and may result in a substantial impact on the progress of solid-state-based quantum communications network. (general)

Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses generated in a gas-filled hollow-core photonic crystal fiber

Energy Technology Data Exchange (ETDEWEB)

Bromberger, H., E-mail: Hubertus.Bromberger@mpsd.mpg.de; Liu, H.; Chávez-Cervantes, M.; Gierz, I. [Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg (Germany); Ermolov, A.; Belli, F.; Abdolvand, A.; Russell, P. St. J.; Travers, J. C. [Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Calegari, F. [Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg (Germany); Institute for Photonics and Nanotechnologies, IFN-CNR, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Li, M. T.; Lin, C. T. [Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart (Germany); Cavalleri, A. [Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg (Germany); Clarendon Laboratory, Department of Physics, University of Oxford, Parks Rd. Oxford OX1 3PU (United Kingdom)

2015-08-31

A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few μJ energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi{sub 2}Se{sub 3} with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude gain in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with photon energies that cover the first Brillouin zone of most materials.

Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses generated in a gas-filled hollow-core photonic crystal fiber

International Nuclear Information System (INIS)

Bromberger, H.; Liu, H.; Chávez-Cervantes, M.; Gierz, I.; Ermolov, A.; Belli, F.; Abdolvand, A.; Russell, P. St. J.; Travers, J. C.; Calegari, F.; Li, M. T.; Lin, C. T.; Cavalleri, A.

2015-01-01

A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gas-filled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few μJ energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi 2 Se 3 with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude gain in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with photon energies that cover the first Brillouin zone of most materials

Multiply excited molecules produced by photon and electron interactions

International Nuclear Information System (INIS)

Odagiri, T.; Kouchi, N.

2006-01-01

The photon and electron interactions with molecules resulting in the formation of multiply excited molecules and the subsequent decay are subjects of great interest because the independent electron model and Born-Oppenheimer approximation are much less reliable for the multiply excited states of molecules than for the ground and lower excited electronic states. We have three methods to observe and investigate multiply excited molecules: 1) Measurements of the cross sections for the emission of fluorescence emitted by neutral fragments in the photoexcitation of molecules as a function of incident photon energy [1-3], 2) Measurements of the electron energy-loss spectra tagged with the fluorescence photons emitted by neutral fragments [4], 3) Measurements of the cross sections for generating a pair of photons in absorption of a single photon by a molecule as a function of incident photon energy [5-7]. Multiply excited states degenerate with ionization continua, which make a large contribution in the cross section curve involving ionization processes. The key point of our methods is hence that we measure cross sections free from ionization. The feature of multiply excited states is noticeable in such a cross section curve. Recently we have measured: i) the cross sections for the emission of the Lyman- fluorescence in the photoexcitation of CH 4 as a function of incident photon energy in the range 18-51 eV, ii) the electron energy-loss spectrum of CH 4 tagged with the Lyman-photons at 80 eV incident electron energy and 10 electron scattering angle in the range of the energy loss 20-45 eV, in order to understand the formation and decay of the doubly excited methane in photon and electron interactions. [8] The results are summarized in this paper and the simultaneous excitation of two electrons by electron interaction is compared with that by photon interaction in terms of the oscillator strength. (authors)

Photonic Structure-Integrated Two-Dimensional Material Optoelectronics

Directory of Open Access Journals (Sweden)

Tianjiao Wang

2016-12-01

Full Text Available The rapid development and unique properties of two-dimensional (2D materials, such as graphene, phosphorene and transition metal dichalcogenides enable them to become intriguing candidates for future optoelectronic applications. To maximize the potential of 2D material-based optoelectronics, various photonic structures are integrated to form photonic structure/2D material hybrid systems so that the device performance can be manipulated in controllable ways. Here, we first introduce the photocurrent-generation mechanisms of 2D material-based optoelectronics and their performance. We then offer an overview and evaluation of the state-of-the-art of hybrid systems, where 2D material optoelectronics are integrated with photonic structures, especially plasmonic nanostructures, photonic waveguides and crystals. By combining with those photonic structures, the performance of 2D material optoelectronics can be further enhanced, and on the other side, a high-performance modulator can be achieved by electrostatically tuning 2D materials. Finally, 2D material-based photodetector can also become an efficient probe to learn the light-matter interactions of photonic structures. Those hybrid systems combine the advantages of 2D materials and photonic structures, providing further capacity for high-performance optoelectronics.

Measurement of the quantum superposition state of an imaging ensemble of photons prepared in orbital angular momentum states using a phase-diversity method

International Nuclear Information System (INIS)

Uribe-Patarroyo, Nestor; Alvarez-Herrero, Alberto; Belenguer, Tomas

2010-01-01

We propose the use of a phase-diversity technique to estimate the orbital angular momentum (OAM) superposition state of an ensemble of photons that passes through an optical system, proceeding from an extended object. The phase-diversity technique permits the estimation of the optical transfer function (OTF) of an imaging optical system. As the OTF is derived directly from the wave-front characteristics of the observed light, we redefine the phase-diversity technique in terms of a superposition of OAM states. We test this new technique experimentally and find coherent results among different tests, which gives us confidence in the estimation of the photon ensemble state. We find that this technique not only allows us to estimate the square of the amplitude of each OAM state, but also the relative phases among all states, thus providing complete information about the quantum state of the photons. This technique could be used to measure the OAM spectrum of extended objects in astronomy or in an optical communication scheme using OAM states. In this sense, the use of extended images could lead to new techniques in which the communication is further multiplexed along the field.

Sub-bandgap photonic base current method for characterization of interface states at heterointerfaces in heterojunction bipolar transistors

International Nuclear Information System (INIS)

Shin, H. T.; Kim, K. H.; Kim, K. S.

2004-01-01

In this paper, we propose a novel photonic base current analysis method to characterize the interface states in heterojunction bipolar transistors (HBTs) by using the photonic I-V characteristics under sub-bandgap photonic excitation. For the photonic current-voltage characterization of HBTs, an optical source with a photon energy less than the bandgap energy of Al 0.3 Ga 0.7 As and GaAs (E ph = 0.95 eV g,AlGaAs = 1.79 eV, E g,GaAs = 1.45 eV) is employed for the characterization of the interface states distributed in the photo-responsive energy band (E C - 0.95 ≤ E it ≤ E C ) in emitter-base heterojunction at HBTs. The proposed novel method, which is applied to bipolar junction transistors for the first time, is simple, and an accurate analysis of interface traps in HBTs is possible. By using the photonic base-current and the dark-base-current, we qualitatively analyze the interface trap at the Al 0.3 Ga 0.7 As/GaAs heterojunction interface in HBTs.

High-fidelity teleportation of continuous-variable quantum States using delocalized single photons

DEFF Research Database (Denmark)

Andersen, Ulrik L; Ralph, Timothy C

2013-01-01

Traditional continuous-variable teleportation can only approach unit fidelity in the limit of an infinite (and unphysical) amount of squeezing. We describe a new method for continuous-variable teleportation that approaches unit fidelity with finite resources. The protocol is not based on squeezed...... states as in traditional teleportation but on an ensemble of single photon entangled states. We characterize the teleportation scheme with coherent states, mesoscopic superposition states, and two-mode squeezed states and we find several situations in which near-unity teleportation fidelity can...

Multi-photon absorption limits to heralded single photon sources

Science.gov (United States)

Husko, Chad A.; Clark, Alex S.; Collins, Matthew J.; De Rossi, Alfredo; Combrié, Sylvain; Lehoucq, Gaëlle; Rey, Isabella H.; Krauss, Thomas F.; Xiong, Chunle; Eggleton, Benjamin J.

2013-01-01

Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g(2)(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources. PMID:24186400

Generation and measurement of nonclassical states by quantum Fock filter

International Nuclear Information System (INIS)

D'Ariano, G.M.; Maccone, L.; Paris, M.G.A.; Sacchi, M.F.

1999-01-01

We study a novel optical setup which selects a specific Fock component from a generic input state. The device allows to synthesize number states and superpositions of few number states, and to measure the photon distribution and the density matrix of a generic signal. (Authors)

Hadron production in photon-photon collisions

International Nuclear Information System (INIS)

Pandita, P.N.; Singh, Y.

1976-01-01

We analyze deep-inelastic photon-photon collisions via the two-photon mechanism in electron-positron (-electron) colliding beams in a form especially suitable for experimental analysis. It is shown that by a helicity analysis similar to that used in electroproduction experiments, we can separate five of the eight structure functions describing the process γ* + γ* → hadrons. The helicity cross sections for this process and for the process with one real photon (inelastic electron-photon scattering) are related to structure functions, and are evaluated using quark light-cone algebra. There are anomalous contributions to the structure functions for the inelastic electron-photon scattering which arise both in parton as well as generalized vector-meson-dominance models. This suggests a connection between these two types of models for photon-photon scattering. Further, we use vector-meson dominance to construct a sum rule for sigma/sub gamma//sub gamma/ /sub arrow-right/ from which it is estimated that roughly 20% of the cross section should be built up from higher-mass vector states. Using a spectral representation for the total transverse cross section, and the ''aligned-jet'' vector-dominance model we achieve a connection, via a ''correspondence principle,'' with the parton model for the hadron multiplicities in photon-photon collisions. We also comment on inclusive pion multiplicities and the approach to scaling for photon-photon processes in the light-cone algebra

Engineering two-photon high-dimensional states through quantum interference

Science.gov (United States)

Zhang, Yingwen; Roux, Filippus S.; Konrad, Thomas; Agnew, Megan; Leach, Jonathan; Forbes, Andrew

2016-01-01

Many protocols in quantum science, for example, linear optical quantum computing, require access to large-scale entangled quantum states. Such systems can be realized through many-particle qubits, but this approach often suffers from scalability problems. An alternative strategy is to consider a lesser number of particles that exist in high-dimensional states. The spatial modes of light are one such candidate that provides access to high-dimensional quantum states, and thus they increase the storage and processing potential of quantum information systems. We demonstrate the controlled engineering of two-photon high-dimensional states entangled in their orbital angular momentum through Hong-Ou-Mandel interference. We prepare a large range of high-dimensional entangled states and implement precise quantum state filtering. We characterize the full quantum state before and after the filter, and are thus able to determine that only the antisymmetric component of the initial state remains. This work paves the way for high-dimensional processing and communication of multiphoton quantum states, for example, in teleportation beyond qubits. PMID:26933685

A new generation of ultra-dense optical I/O for silicon photonics

Science.gov (United States)

Wlodawski, Mitchell S.; Kopp, Victor I.; Park, Jongchul; Singer, Jonathan; Hubner, Eric E.; Neugroschl, Daniel; Chao, Norman; Genack, Azriel Z.

2014-03-01

In response to the optical packaging needs of a rapidly growing silicon photonics market, Chiral Photonics, Inc. (CPI) has developed a new generation of ultra-dense-channel, bi-directional, all-optical, input/output (I/O) couplers that bridge the data transport gap between standard optical fibers and photonic integrated circuits. These couplers, called Pitch Reducing Optical Fiber Arrays (PROFAs), provide a means to simultaneously match both the mode field and channel spacing (i.e. pitch) between an optical fiber array and a photonic integrated circuit (PIC). Both primary methods for optically interfacing with PICs, via vertical grating couplers (VGCs) and edge couplers, can be addressed with PROFAs. PROFAs bring the signal-carrying cores, either multimode or singlemode, of many optical fibers into close proximity within an all-glass device that can provide low loss coupling to on-chip components, including waveguides, gratings, detectors and emitters. Two-dimensional (2D) PROFAs offer more than an order of magnitude enhancement in channel density compared to conventional one-dimensional (1D) fiber arrays. PROFAs can also be used with low vertical profile solutions that simplify optoelectronic packaging while reducing PIC I/O real estate usage requirements. PROFA technology is based on a scalable production process for microforming glass preform assemblies as they are pulled through a small oven. An innovative fiber design, called the "vanishing core," enables tailoring the mode field along the length of the PROFA to meet the coupling needs of disparate waveguide technologies, such as fiber and onchip. Examples of single- and multi-channel couplers fabricated using this technology will be presented.

Observation of Entanglement of a Single Photon with a Trapped Atom

International Nuclear Information System (INIS)

Volz, Juergen; Weber, Markus; Schlenk, Daniel; Rosenfeld, Wenjamin; Vrana, Johannes; Saucke, Karen; Kurtsiefer, Christian; Weinfurter, Harald

2006-01-01

We report the observation of entanglement between a single trapped atom and a single photon at a wavelength suitable for low-loss communication over large distances, thereby achieving a crucial step towards long range quantum networks. To verify the entanglement, we introduce a single atom state analysis. This technique is used for full state tomography of the atom-photon qubit pair. The detection efficiency and the entanglement fidelity are high enough to allow in a next step the generation of entangled atoms at large distances, ready for a final loophole-free Bell experiment

Extension of supercontinuum spectrum, generated in polarization-maintaining photonic crystal fiber, using chirped femtosecond pulses

Science.gov (United States)

Vengelis, Julius; Jarutis, Vygandas; Sirutkaitis, Valdas

2018-01-01

We present results of experimental and numerical investigation of supercontinuum (SC) generation in polarization-maintaining photonic crystal fiber (PCF) using chirped femtosecond pulses. The initial unchirped pump pulse source was a mode-locked Yb:KGW laser generating 52-nJ energy, 110-fs duration pulses at 1030 nm with a 76-MHz repetition rate. The nonlinear medium was a 32-cm-long polarization-maintaining PCF manufactured by NKT Photonics A/S. We demonstrated the influence of pump pulse chirp on spectral characteristics of a SC. We showed that by chirping pump pulses positively or negatively one can obtain a broader SC spectrum than in the case of unchirped pump pulses at the same peak power. Moreover, the extension can be controlled by changing the amount of pump pulse chirp. Numerical simulation results also indicated that pump pulse chirp yields an extension of SC spectrum.

Discrimination of binary coherent states using a homodyne detector and a photon number resolving detector

DEFF Research Database (Denmark)

Wittmann, Christoffer; Andersen, Ulrik Lund; Takeoka, Masahiro

2010-01-01

We investigate quantum measurement strategies capable of discriminating two coherent states probabilistically with significantly smaller error probabilities than can be obtained using nonprobabilistic state discrimination. We apply a postselection strategy to the measurement data of a homodyne...... detector as well as a photon number resolving detector in order to lower the error probability. We compare the two different receivers with an optimal intermediate measurement scheme where the error rate is minimized for a fixed rate of inconclusive results. The photon number resolving (PNR) receiver...

Quantum Anatomy of the Classical Interference of n-Photon States in a Mach-Zehnder Interferometer

International Nuclear Information System (INIS)

Ramírez-Cruz, N; Velázquez, V; Bastarrachea-Magnani, M A

2016-01-01

In this work we present the theory for the quantum interference of states with an arbitrary number of photons in a Mach-Zehnder interferometer. We express the mathematical description of the interference in an algebraic way. We show the interference pattern of an average of a n photons input state corresponds to the classical interference pattern, which tells us the last comes from a quantum interference statistical average. Then, we propose to use this scheme to study the statistical transition from quantum to classical interference. (paper)

Detection-dependent six-photon Holland-Burnett state interference

Science.gov (United States)

Jin, Rui-Bo; Fujiwara, Mikio; Shimizu, Ryosuke; Collins, Robert J.; Buller, Gerald S.; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Takeoka, Masahiro; Sasaki, Masahide

2016-11-01

The NOON state, and its experimental approximation the Holland-Burnett state, have important applications in phase sensing measurement with enhanced sensitivity. However, most of the previous Holland-Burnett state interference (HBSI) experiments only investigated the area of the interference pattern in the region immediately around zero optical path length difference, while the full HBSI pattern over a wide range of optical path length differences has not yet been well explored. In this work, we experimentally and theoretically demonstrate up to six-photon HBSI and study the properties of the interference patterns over a wide range of optical path length differences. It was found that the shape, the coherence time and the visibility of the interference patterns were strongly dependent on the detection schemes. This work paves the way for applications which are based on the envelope of the HBSI pattern, such as quantum spectroscopy and quantum metrology.

Single-Photon Technologies Based on Quantum-Dots in Photonic Crystals

DEFF Research Database (Denmark)

Lehmann, Tau Bernstorff

-photon purity under quasi-resonantexcitation. Furthermore the waveguide based platform demonstrates indistinguishable single-photonsat timescales up to 13 ns.A setup for active demultiplexing of single-photons to a three-fold single-photon state is proposed.Using a fast electro-optical modulator, single...

Photonic Crystals Towards Nanoscale Photonic Devices

CERN Document Server

Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexei; Pagnoux, Dominique

2008-01-01

Just like the periodical crystalline potential in solid state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as cages for storing, filtering or guiding light at the wavelength scale paves the way to the realization of optical and optoelectronic devices with ultimate properties and dimensions. This will contribute towards meeting the demands for greater miniaturization imposed by the processing of an ever increasing number of data. Photonic Crystals will provide students and researchers from different fields with the theoretical background required for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, ranging from optics to microwaves, where photonic crystals have found application. As such, it aims at building bridges between...

Photonic Crystals Towards Nanoscale Photonic Devices

CERN Document Server

Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexis

2005-01-01

Just like the periodical crystalline potential in solid-state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as a cage for storing, filtering or guiding light at the wavelength scale thus paves the way to the realisation of optical and optoelectronic devices with ultimate properties and dimensions. This should contribute toward meeting the demands for a greater miniaturisation that the processing of an ever increasing number of data requires. Photonic Crystals intends at providing students and researchers from different fields with the theoretical background needed for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, from optics to microwaves, where photonic crystals have found applications. As such, it aims at building brid...

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