Physics and Astronomy › Atomic and Molecular Physics, and Optics

Quantum optics and atomic interactions

Works Count: 43339

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Description

This cluster of papers focuses on the phenomenon of slow light propagation and quantum memory in coherent media, particularly using techniques such as electromagnetically induced transparency, optical quantum memory, and photon storage in atomic ensembles. The research explores applications in ultraslow pulses, optical bistability, and quantum entanglement, often involving photonic crystal structures.

Keywords

Electromagnetically Induced Transparency; Slow Light; Quantum Memory; Coherent Optical Media; Atomic Ensembles; Photon Storage; Ultraslow Pulses; Optical Bistability; Quantum Entanglement; Photonic Crystal

Ultraslow Group Velocity and Enhanced Nonlinear Optical Effects in a Coherently Driven Hot Atomic Gas

1999-06-28

Michael M. Kash , Vladimir A. Sautenkov , A. S. Zibrov +6 more

We report the observation of small group velocities of order 90 m/s and large group delays of greater than 0.26 ms, in an optically dense hot rubidium gas ( $\ensuremath{\approx}360\mathrm{K}$). … We report the observation of small group velocities of order 90 m/s and large group delays of greater than 0.26 ms, in an optically dense hot rubidium gas ( $\ensuremath{\approx}360\mathrm{K}$). Media of this kind yield strong nonlinear interactions between very weak optical fields and very sharp spectral features. The result is in agreement with previous studies on nonlinear spectroscopy of dense coherent media.

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Gain-assisted superluminal light propagation

2000-07-20

L. J. Wang , A. Kuzmich , Arthur Dogariu

<i>Fundamentals of Quantum Optics</i>

1969-12-01

John R. Klauder , E. C. G. Sudarshan , Marvin M. Miller

Optical quantum memory

2009-11-30

A. I. Lvovsky , Barry C. Sanders , Wolfgang Tittel

Optical Resonance and Two-level Atoms

1975-12-01

B. K. Garside

"Optical Resonance and Two-level Atoms." Optica Acta: International Journal of Optics, 22(12), pp. 1041–1042 "Optical Resonance and Two-level Atoms." Optica Acta: International Journal of Optics, 22(12), pp. 1041–1042

Internal Reflection Spectroscopy

1967-01-01

Paul A. Wilks , Tomas Hirschfeld

(1967). Internal Reflection Spectroscopy. Applied Spectroscopy Reviews: Vol. 1, No. 1, pp. 99-130. (1967). Internal Reflection Spectroscopy. Applied Spectroscopy Reviews: Vol. 1, No. 1, pp. 99-130.

Spin squeezing and reduced quantum noise in spectroscopy

1992-12-01

D. J. Wineland , J. J. Bollinger , Wayne M. Itano +2 more

We investigate the quantum-mechanical noise in spectroscopic experiments on ensembles of N two-level (or spin-1/2) systems where transitions are detected by measuring changes in state population. By preparing correlated states, … We investigate the quantum-mechanical noise in spectroscopic experiments on ensembles of N two-level (or spin-1/2) systems where transitions are detected by measuring changes in state population. By preparing correlated states, here called squeezed spin states, we can increase the signal-to-noise ratio in spectroscopy (by approximately ${\mathit{N}}^{1/2}$ in certain cases) over that found in experiments using uncorrelated states. Possible experimental demonstrations of this enhancement are discussed.

Fabry–Perot cavity pulsed Fourier transform microwave spectrometer with a pulsed nozzle particle source

1981-01-01

T. J. Balle , W. H. Flygare

We describe the design, construction, and operation of a new type of microwave spectrograph which allows the measurement of the resonant transitions of transient or otherwise short-lived species. The spectrograph … We describe the design, construction, and operation of a new type of microwave spectrograph which allows the measurement of the resonant transitions of transient or otherwise short-lived species. The spectrograph is composed of three parts: a Fabry–Perot cavity, a pulsed supersonic nozzle as a source for the sample, and the pulsed microwave Fourier transform method. Following a detailed discussion of the three above components in the spectrograph, the operation of the entire system is described and several examples are given.

Steady States and Quasienergies of a Quantum-Mechanical System in an Oscillating Field

1973-06-01

H. Sambe

A general formalism is presented for a system whose Hamiltonian is periodic in time. The formalism is intended to deal with the interactions between bond electrons and an external electromagnetic … A general formalism is presented for a system whose Hamiltonian is periodic in time. The formalism is intended to deal with the interactions between bond electrons and an external electromagnetic field, which can be treated semiclassically, such as electric and magnetic polarizations, optical rotation, and transitions among discrete levels. A particular bound-state solution of the Schr\"odinger equation which belongs to an irreducible representation of the time-translation symmetry group is defined as a steady state, and the characteristic number of the irreducible representation as a quasienergy. It is shown that the defined steady states and quasienergies behave in a newly constructed Hilbert space like stationary states and energies of a conservative system in many respects. It is also shown that for a resonant case the unperturbed quasienergy becomes degenerate and the transitions among discrete levels can be accounted for by the familiar degenerate perturbation procedure. Using a suitable Hilbert space, the steady states are established as firmly as the stationary states stand in the theory of a conservative system.

Spectra and Energy Levels of Rare Earth Ions in Crystals

1970-03-01

G. H. Dieke , R. A. Satten

First Page First Page

Long-Transient Effects in Lasers with Inserted Liquid Samples

1965-01-01

J. P. Gordon , R. C. C. Leite , E. F. Moore +2 more

Buildup and decay transients were observed when polar or nonpolar liquid cells were placed within the resonator of a helium—neon laser operating in the red at 6328 Å. Similar but … Buildup and decay transients were observed when polar or nonpolar liquid cells were placed within the resonator of a helium—neon laser operating in the red at 6328 Å. Similar but smaller effects were also observed with two solids. Time constants were the order of a few seconds for all materials, which suggests a thermal phenomenon, but general heating effects were ruled out by the strong localization of the phenomenon. Transverse motion of the cell by about one beam width caused new transients similar to the initial ones. It is believed that the effects are caused by absorption of the red light in the material, producing a local heating in the vicinity of the beam and a lens effect arising from the transverse gradient of refractive index. Absorptions of 10−3 to 10−4 parts per centimeter are sufficient to produce the effects, and are believed to be reasonable values for the materials studied. One of the most important applications may in fact be for the measurement of small absorbancies. The experiments are described, and analysis of the lens effect from absorption is given. Alternate explanations which were considered are stated briefly.

Self-Induced Transparency

1969-07-10

S. L. McCall , E. L. Hahn

Above a critical power threshold for a given pulse width, a short pulse of coherent traveling-wave optical radiation is observed to propagate with anomalously low energy loss while at resonance … Above a critical power threshold for a given pulse width, a short pulse of coherent traveling-wave optical radiation is observed to propagate with anomalously low energy loss while at resonance with a two-quantum-level system of absorbers. The line shape of the resonant system is determined by inhomogeneous broadening, and the pulse width is short compared to dissipative relaxation times. A new mechanism of self-induced transparency, which accounts for the low energy loss, is analyzed in the ideal limit of a plane wave which excites a resonant medium with no damping present. The stable condition of transparency results after the traversal of the pulse through a few classical absorption lengths into the medium. This condition exists when the initial pulse has evolved into a symmetric hyperbolic-secant pulse function of time and distance, and has the area characteristic of a "$2\ensuremath{\pi}$ pulse." Ideal transparency then persists when coherent induced absorption of pulse energy during the first half of the pulse is followed by coherent induced emission of the same amount of energy back into the beam direction during the second half of the pulse. The effects of dissipative relaxation times upon pulse energy, pulse area, and pulse delay time are analyzed to first order in the ratio of short pulse width to long damping time. The analysis shows that the $2\ensuremath{\pi}$ pulse condition can be maintained if losses caused by damping are compensated by beam focusing. In an amplifying inhomogeneously broadened medium an analytic "$\ensuremath{\pi}$ pulse area" solution is presented in the limit of a sharp leading edge of the pulse. The dynamics of self-induced transparency are studied for the particular effects of Doppler velocities upon a resonant gas. The analysis of transparency for random orientations of dipole moments associated with degenerate rotational states yields modified forms of self-induced transparency behavior, which indicates a finite pulse energy loss as a function of distance in some cases. The effect of self-induced transparency on the photon echo is considered. Experimental observations of self-induced transparency have been made in a ruby sample at resonance with a pulsed ruby-laser beam. Single and multiple $2\ensuremath{\pi}$ pulse outputs have been observed, and pulse areas measured in the range of $2\ensuremath{\pi}$. The experimental results are compared with the predictions of the ideal-plane-wave theory. Deviations from the ideal-plane-wave theory are discussed. An analysis is made of the effect of a transverse mode of the propagating beam upon the transparency properties of the pulse.

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Dark-State Polaritons in Electromagnetically Induced Transparency

2000-05-29

Michael Fleischhauer , Mikhail D. Lukin

We identify form-stable coupled excitations of light and matter ("dark-state polaritons") associated with the propagation of quantum fields in electromagnetically induced transparency. The properties of dark-state polaritons such as the … We identify form-stable coupled excitations of light and matter ("dark-state polaritons") associated with the propagation of quantum fields in electromagnetically induced transparency. The properties of dark-state polaritons such as the group velocity are determined by the mixing angle between light and matter components and can be controlled by an external coherent field as the pulse propagates. In particular, light pulses can be decelerated and "trapped" in which case their shape and quantum state are mapped onto metastable collective states of matter. Possible applications of this reversible coherent-control technique are discussed.

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Strongly Interacting Photons in a Nonlinear Cavity

1997-08-25

Ataç İmamoğlu , Holger Schmidt , G. T. Woods +1 more

We consider the dynamics of single photons in a nonlinear optical cavity. When the Kerr nonlinearities of atomic dark resonances are utilized, the cavity mode is well described by a … We consider the dynamics of single photons in a nonlinear optical cavity. When the Kerr nonlinearities of atomic dark resonances are utilized, the cavity mode is well described by a spin- $1/2$ Hamiltonian. We show that it is possible to achieve coherent control of the cavity-mode wave function using $\ensuremath{\pi}$ pulses for single photons that switch the state of the cavity with very high accuracy. The underlying physics is best understood as the nonlinearity induced anticorrelation between single-photon injection/emission events, which we refer to as photon blockade. We also propose a method which uses these strong dispersive interactions to realize a single-photon turnstile device.

Infrared Study of Adsorbed Molecules on Metal Surfaces by Reflection Techniques

1966-01-01

Robert G. Greenler

The problem of obtaining the infrared spectrum of a molecular monolayer adsorbed on a bulk metal is discussed. The intensity of an infrared absorption band in radiation reflected from the … The problem of obtaining the infrared spectrum of a molecular monolayer adsorbed on a bulk metal is discussed. The intensity of an infrared absorption band in radiation reflected from the surface is calculated for (a) various optical constants of the adsorbed layer and the metal, (b) various thicknesses of the adsorbed layer, (c) various angles of incidence, and (d) both states of polarization of the incident radiation. The absorption factor for infrared radiation polarized parallel to the plane of incidence typically has a peak at an incident angle of about 88°, where the absorption is 5000 times greater than at normal incidence. The absorption of a thin layer by the reflection technique, at optimum conditions, is calculated to be about 25 times greater than by transmission through the unsupported film at normal incidence.

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Observation of electromagnetically induced transparency

1991-05-20

Klaus J. Boller , Ataç İmamoğlu , Stephen Harris

We report the first demonstration of a technique by which an optically thick medium may be rendered transparent. The transparency results from a destructive interference of two dressed states which … We report the first demonstration of a technique by which an optically thick medium may be rendered transparent. The transparency results from a destructive interference of two dressed states which are created by applying a temporally smooth coupling laser between a bound state of an atom and the upper state of the transition which is to be made transparent. The transmittance of an autoionizing (ultraviolet) transition in Sr is changed from exp(-20) without a coupling laser present to exp(-1) in the presence of a coupling laser.

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Coherent population transfer among quantum states of atoms and molecules

1998-07-01

K. Bergmann , H. Theuer , Bruce W. Shore

The authors discuss the technique of stimulated Raman adiabatic passage (STIRAP), a method of using partially overlapping pulses (from pump and Stokes lasers) to produce complete population transfer between two … The authors discuss the technique of stimulated Raman adiabatic passage (STIRAP), a method of using partially overlapping pulses (from pump and Stokes lasers) to produce complete population transfer between two quantum states of an atom or molecule. The procedure relies on the initial creation of a coherence (a population-trapping state) with subsequent adiabatic evolution. The authors present the basic theory, with some extensions, and then describe examples of experimental utilization. They note some applications of the technique not only to preparation of selected states for reaction studies, but also to quantum optics and atom optics.

Degenerate quantum-beat laser: Lasing without inversion and inversion without lasing

1989-06-12

Marlan O. Scully , Shi-Yao Zhu , Athanasios Gavrielides

A single lasing mode driven by a three-level ``quantum-beat'' atomic configuration can show gain without population inversion or optical absorption into an excited state without spontaneous or stimulated emission. A single lasing mode driven by a three-level ``quantum-beat'' atomic configuration can show gain without population inversion or optical absorption into an excited state without spontaneous or stimulated emission.

Exact Solution for an<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>N</mml:mi></mml:math>-Molecule—Radiation-Field Hamiltonian

1968-06-10

M. T. Tavis , F.W. Cummings

The exact solution for a problem of $N$ identical two-level molecules interacting through a dipole coupling with a single-mode quantized radiation field at resonance is given. Approximate expressions for the … The exact solution for a problem of $N$ identical two-level molecules interacting through a dipole coupling with a single-mode quantized radiation field at resonance is given. Approximate expressions for the eigenvectors and eigenvalues for the ground and low-lying excited states, as well as the most highly excited states, are developed and compared with the exact results.

Nonlinear Optics at Low Light Levels

1999-06-07

Stephen Harris , Lene Vestergaard Hau

We show how the combination of electromagnetically induced transparency based nonlinear optics and cold atom technology, under conditions of ultraslow light propagation, allows nonlinear processes at energies of a few … We show how the combination of electromagnetically induced transparency based nonlinear optics and cold atom technology, under conditions of ultraslow light propagation, allows nonlinear processes at energies of a few photons per atomic cross section.

Special points for Brillouin-zone integrations

1976-06-15

Hendrik J. Monkhorst , J.D. Pack

A method is given for generating sets of special points in the Brillouin zone which provides an efficient means of integrating periodic functions of the wave vector. The integration can … A method is given for generating sets of special points in the Brillouin zone which provides an efficient means of integrating periodic functions of the wave vector. The integration can be over the entire Brillouin zone or over specified portions thereof. This method also has applications in spectral and density-of-state calculations. The relationships to the Chadi-Cohen and Gilat-Raubenheimer methods are indicated.

Theory of the Contribution of Excitons to the Complex Dielectric Constant of Crystals

1958-12-01

J. J. Hopfield

It is shown that the ordinary semiclassical theory of the absorption of light by exciton states is not completely satisfactory (in contrast to the case of absorption due to interband … It is shown that the ordinary semiclassical theory of the absorption of light by exciton states is not completely satisfactory (in contrast to the case of absorption due to interband transitions). A more complete theory is developed. It is shown that excitons are approximate bosons, and, in interaction with the electromagnetic field, the exciton field plays the role of the classical polarization field. The eigenstates of the system of crystal and radiation field are mixtures of photons and excitons. The ordinary one-quantum optical lifetime of an excitation is infinite. Absorption occurs only when "three-body" processes are introduced. The theory includes "local field" effects, leading to the Lorentz local field correction when it is applicable. A Smakula equation for the oscillator strength in terms of the integrated absorption constant is derived.

Power Spectrum of Light Scattered by Two-Level Systems

1969-12-25

B. R. Mollow

The power spectrum of the light scattered by a two-level atom driven near resonance by a monochromatic classical electric field is evaluated. The atom is assumed to relax to equilibrium … The power spectrum of the light scattered by a two-level atom driven near resonance by a monochromatic classical electric field is evaluated. The atom is assumed to relax to equilibrium with the driving field via radiation damping, which is treated by explicitly coupling the atom to the quantized electromagnetic field modes. The power spectrum of the scattered field is directly obtainable from the two-time atomic dipole moment correlation function, which is evaluated by a method based on a Markoff-type assumption analogous to that used to evaluate the time evolution of single-time atomic expectation values.

On the superradiant phase transition for molecules in a quantized radiation field: the dicke maser model

1973-04-01

K. Hepp , Élliott H. Lieb

Storage of Light in Atomic Vapor

2001-01-29

David F. Phillips , A. Fleischhauer , A. Mair +2 more

We report an experiment in which a light pulse is effectively decelerated and trapped in a vapor of Rb atoms, stored for a controlled period of time, and then released … We report an experiment in which a light pulse is effectively decelerated and trapped in a vapor of Rb atoms, stored for a controlled period of time, and then released on demand. We accomplish this "storage of light" by dynamically reducing the group velocity of the light pulse to zero, so that the coherent excitation of the light is reversibly mapped into a Zeeman (spin) coherence of the Rb vapor.

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Squeezed atomic states and projection noise in spectroscopy

1994-07-01

D. J. Wineland , J. J. Bollinger , Wayne M. Itano +1 more

We investigate the properties of angular-momentum states which yield high sensitivity to rotation. We discuss the application of these ``squeezed-spin'' or correlated-particle states to spectroscopy. Transitions in an ensemble of … We investigate the properties of angular-momentum states which yield high sensitivity to rotation. We discuss the application of these ``squeezed-spin'' or correlated-particle states to spectroscopy. Transitions in an ensemble of N two-level (or, equivalently, spin-1/2) particles are assumed to be detected by observing changes in the state populations of the particles (population spectroscopy). When the particles' states are detected with 100% efficiency, the fundamental limiting noise is projection noise, the noise associated with the quantum fluctuations in the measured populations. If the particles are first prepared in particular quantum-mechanically correlated states, we find that the signal-to-noise ratio can be improved over the case of initially uncorrelated particles. We have investigated spectroscopy for a particular case of Ramsey's separated oscillatory method where the radiation pulse lengths are short compared to the time between pulses. We introduce a squeezing parameter ${\ensuremath{\xi}}_{\mathit{R}}$ which is the ratio of the statistical uncertainty in the determination of the resonance frequency when using correlated states vs that when using uncorrelated states. More generally, this squeezing parameter quantifies the sensitivity of an angular-momentum state to rotation. Other squeezing parameters which are relevant for use in other contexts can be defined. We discuss certain states which exhibit squeezing parameters ${\ensuremath{\xi}}_{\mathit{R}}$\ensuremath{\simeq}${\mathit{N}}^{\mathrm{\ensuremath{-}}1/2}$. We investigate possible experimental schemes for generation of squeezed-spin states which might be applied to the spectroscopy of trapped atomic ions. We find that applying a Jaynes-Cummings--type coupling between the ensemble of two-level systems and a suitably prepared harmonic oscillator results in correlated states with ${\ensuremath{\xi}}_{\mathit{R}}$1.

V Coherent Population Trapping in Laser Spectroscopy

1996-01-01

E. Arimondo

Perturbation theory of the non-linear optical polarization of an isolated system

1971-01-01

Brian J. Orr , John F. Ward

The non-linear optical polarization of an isolated atom or molecule is treated, giving careful consideration to secular and resonant terms in the perturbation expansion. The Method of Averages introduced by … The non-linear optical polarization of an isolated atom or molecule is treated, giving careful consideration to secular and resonant terms in the perturbation expansion. The Method of Averages introduced by Bogoliubov and Mitropolsky is used. The case where resonance-induced excited state populations are negligible, which is relevant to a wide range of non-linear optical experiments, is examined in detail for polarizations through third order in the perturbing fields. This yields concise expressions which are valid for any combination of applied field frequencies, including static fields.

Photonic Spin Hall Effect at Metasurfaces

2013-03-21

Xiaobo Yin , Ziliang Ye , Junsuk Rho +2 more

The spin Hall effect (SHE) of light is very weak because of the extremely small photon momentum and spin-orbit interaction. Here, we report a strong photonic SHE resulting in a … The spin Hall effect (SHE) of light is very weak because of the extremely small photon momentum and spin-orbit interaction. Here, we report a strong photonic SHE resulting in a measured large splitting of polarized light at metasurfaces. The rapidly varying phase discontinuities along a metasurface, breaking the axial symmetry of the system, enable the direct observation of large transverse motion of circularly polarized light, even at normal incidence. The strong spin-orbit interaction deviates the polarized light from the trajectory prescribed by the ordinary Fermat principle. Such a strong and broadband photonic SHE may provide a route for exploiting the spin and orbit angular momentum of light for information processing and communication.

The Adiabatic Phase and Pancharatnam's Phase for Polarized Light

1987-11-01

Michael Berry

Abstract In 1955 Pancharatnam showed that a cyclic change in the state of polarization of light is accompanied by a phase shift determined by the geometry of the cycle as … Abstract In 1955 Pancharatnam showed that a cyclic change in the state of polarization of light is accompanied by a phase shift determined by the geometry of the cycle as represented on the Poincaré sphere. The phase owes its existence to the non-transitivity of Pancharatnam's connection between different states of polarization. Using the algebra of spinors and 2 × 2 Hermitian matrices, the precise relation is established between Pancharatnam's phase and the recently discovered phase change for slowly cycled quantum systems. The polarization phase is an optical analogue of the Aharonov-Bohm effect. For slow changes of polarization, the connection leading to the phase is derived from Maxwell's equations for a twisted dielectric. Pancharatnam's phase is contrasted with the phase change of circularly polarized light whose direction is cycled (e.g. when guided in a coiled optical fibre).

Electromagnetically induced transparency: Optics in coherent media

2005-07-12

Michael Fleischhauer , Ataç İmamoğlu , J. P. Marangos

Coherent preparation by laser light of quantum states of atoms and molecules can lead to quantum interference in the amplitudes of optical transitions. In this way the optical properties of … Coherent preparation by laser light of quantum states of atoms and molecules can lead to quantum interference in the amplitudes of optical transitions. In this way the optical properties of a medium can be dramatically modified, leading to electromagnetically induced transparency and related effects, which have placed gas-phase systems at the center of recent advances in the development of media with radically new optical properties. This article reviews these advances and the new possibilities they offer for nonlinear optics and quantum information science. As a basis for the theory of electromagnetically induced transparency the authors consider the atomic dynamics and the optical response of the medium to a continuous-wave laser. They then discuss pulse propagation and the adiabatic evolution of field-coupled states and show how coherently prepared media can be used to improve frequency conversion in nonlinear optical mixing experiments. The extension of these concepts to very weak optical fields in the few-photon limit is then examined. The review concludes with a discussion of future prospects and potential new applications.

Active control of slow light on a chip with photonic crystal waveguides

2005-11-01

Yurii A. Vlasov , M. O’Boyle , Hendrik F. Hamann +1 more

Self-Induced Transparency by Pulsed Coherent Light

1967-05-22

S. L. McCall , E. L. Hahn

Zur Theorie des Durchgangs schneller Korpuskularstrahlen durch Materie

1930-01-01

Hans A. Bethe

Theory of an Optical Maser

1964-06-15

Willis E. Lamb

A theoretical model for the behavior of an optical maser is presented in which the electromagnetic field is treated classically, and the active medium is made up of thermally moving … A theoretical model for the behavior of an optical maser is presented in which the electromagnetic field is treated classically, and the active medium is made up of thermally moving atoms which acquire nonlinear electric dipole moments under the action of the field according to the laws of quantum mechanics. The corresponding macroscopic electric polarization of the medium acts as a source for an electromagnetic field. The self-consistency requirement that a quasistationary field should be sustained by the induced polarization leads to equations which determine the amplitudes and frequencies of multimode oscillation as functions of the various parameters characterizing the maser. Among the results obtained are: threshold conditions, single-mode output as a function of cavity tuning, frequency pulling and pushing, mode competition phenomena including frequency locking, production of combination tones, and population pulsations. A more approximate discussion of maser action using rate equations is also given in which the concept of "hole burning" plays a role.

L<scp>ASER</scp>-I<scp>NDUCED</scp> P<scp>OPULATION</scp> T<scp>RANSFER BY</scp> A<scp>DIABATIC</scp> P<scp>ASSAGE</scp> T<scp>ECHNIQUES</scp>

2001-10-01

Nikolay V. Vitanov , Thomas Halfmann , Bruce W. Shore +1 more

We review some basic techniques for laser-induced adiabatic population transfer between discrete quantum states in atoms and molecules. We review some basic techniques for laser-induced adiabatic population transfer between discrete quantum states in atoms and molecules.

Quantum interface between light and atomic ensembles

2010-04-05

Klemens Hammerer , Anders S. Sørensen , E. S. Polzik

During the past decade the interaction of light with multi-atom ensembles has attracted a lot of attention as a basic building block for quantum information processing and quantum state engineering. … During the past decade the interaction of light with multi-atom ensembles has attracted a lot of attention as a basic building block for quantum information processing and quantum state engineering. The field started with the realization that optically thick free space ensembles can be efficiently interfaced with quantum optical fields. By now the atomic ensemble - light interfaces have become a powerful alternative to the cavity-enhanced interaction of light with single atoms. We discuss various mechanisms used for the quantum interface, including quantum nondemolition or Faraday interaction, quantum measurement and feedback, Raman interaction and electromagnetically induced transparency. The paper provides a common theoretical frame for these processes, describes basic experimental techniques and media used for quantum interfaces, and reviews several key experiments on quantum memory for light, quantum entanglement between atomic ensembles and light, and quantum teleportation with atomic ensembles. We discuss the two types of quantum measurements which are most important for the interface: homodyne detection and photon counting. The paper concludes with an outlook on the future of atomic ensembles as an enabling technology in quantum information processing.

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Giant Kerr nonlinearities obtained by electromagnetically induced transparency

1996-12-01

Holger Schmidt , Ataç İmamoğlu

We analyze a cross-phase modulation (XPM) scheme that exhibits a giant, resonantly enhanced nonlinearity, along with vanishing linear susceptibilities. The proposed atomic system uses an electromagnetically induced transparency and is … We analyze a cross-phase modulation (XPM) scheme that exhibits a giant, resonantly enhanced nonlinearity, along with vanishing linear susceptibilities. The proposed atomic system uses an electromagnetically induced transparency and is limited only by two-photon absorption. We predict dramatic improvement by several orders of magnitude for conditional phase shifts in XPM, and the system has possible applications in quantum nondemolition measurements and for quantum logic gates.

Observation of coherent optical information storage in an atomic medium using halted light pulses

2001-01-01

Chien Liu , Zachary Dutton , Cyrus H. Behroozi +1 more

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Multiple absorption of laser photons by atoms

1973-04-01

F. H. M. Faisal

Applying a space translation operation, the Schrodinger equation for an atom in an electromagnetic field is solved with sufficient accuracy to obtain probabilities for multiple absorption of photons from a … Applying a space translation operation, the Schrodinger equation for an atom in an electromagnetic field is solved with sufficient accuracy to obtain probabilities for multiple absorption of photons from a monochromatic laser beam of arbitrary intensity or frequency. It is shown that the derived expression for the N-photon T-matrix contains the usual single photon matrix elements given by the perturbation theory and that the perturbative result is obtained in the limit of low intensity. Other explicit examples are considered. The conditions of applicability of the method are specified.

Measuring the Quantum State of Light

1998-06-01

Ulf Leonhardt , M. Beck

First Page First Page

Absorption and Scattering of Light by Small Particles

1984-01-01

Robert G. W. Brown

"Absorption and Scattering of Light by Small Particles." Optica Acta: International Journal of Optics, 31(1), p. 3 "Absorption and Scattering of Light by Small Particles." Optica Acta: International Journal of Optics, 31(1), p. 3

Quantum Inverse Scattering Method and Correlation Functions

1993-08-19

V. E. Korepin , N. M. Bogoliubov , A. G. Izergin

The quantum inverse scattering method is a means of finding exact solutions of two-dimensional models in quantum field theory and statistical physics (such as the sine-Gordon equation or the quantum … The quantum inverse scattering method is a means of finding exact solutions of two-dimensional models in quantum field theory and statistical physics (such as the sine-Gordon equation or the quantum non-linear Schrödinger equation). These models are the subject of much attention amongst physicists and mathematicians. The present work is an introduction to this important and exciting area. It consists of four parts. The first deals with the Bethe ansatz and calculation of physical quantities. The authors then tackle the theory of the quantum inverse scattering method before applying it in the second half of the book to the calculation of correlation functions. This is one of the most important applications of the method and the authors have made significant contributions to the area. Here they describe some of the most recent and general approaches and include some new results. The book will be essential reading for all mathematical physicists working in field theory and statistical physics.

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Electromagnetically Induced Transparency

1997-07-01

Stephen Harris

Electromagnetically induced transparency is a technique for eliminating the effect of a medium on a propagating beam of electromagnetic radiation. EIT may also be used, but under more limited conditions, … Electromagnetically induced transparency is a technique for eliminating the effect of a medium on a propagating beam of electromagnetic radiation. EIT may also be used, but under more limited conditions, to eliminate optical self-focusing and defocusing and to improve the transmission of laser beams through inhomogeneous refracting gases and metal vapors, as figure 1 illustrates. The technique may be used to create large populations of coherently driven uniformly phased atoms, thereby making possible new types of optoelectronic devices.

The Quantum Theory of Light

2000-09-07

R. Loudon

Abstract This third edition, like its two predecessors, provides a detailed account of the basic theory needed to understand the properties of light and its interactions with atoms, in particular … Abstract This third edition, like its two predecessors, provides a detailed account of the basic theory needed to understand the properties of light and its interactions with atoms, in particular the many nonclassical effects that have now been observed in quantum-optical experiments. The earlier chapters describe the quantum mechanics of various optical processes, leading from the classical representation of the electromagnetic field to the quantum theory of light. The later chapters develop the theoretical descriptions of some of the key experiments in quantum optics. Over half of the material in this third edition is new. It includes topics that have come into prominence over the last two decades, such as the beamsplitter theory, squeezed light, two-photon interference, balanced homodyne detection, travelling-wave attenuation and amplification, quantum jumps, and the ranges of nonliner optical processes important in the generation of nonclassical light. The book is written as a textbook, with the treatment as a whole appropriate for graduate or postgraduate students, while earlier chapters are also suitable for final- year undergraduates. Over 100 problems help to intensify the understanding of the material presented.

Molecular spectroscopy of the triplet state

1969-01-01

S. P. McGlynn , T. AZUMI , Minoru Kinoshita

Transmission resonances in scattering by δ′-like combs

2025-06-24

Yuriy Golovaty , Rostyslav Hryniv , Stanislav Lavrynenko | Journal of Physics A Mathematical and Theoretical

Abstract We introduce a new exactly solvable model in quantum mechanics that describes the propagation of particles through a potential field created by regularly spaced $\delta'$-type point interactions, which model … Abstract We introduce a new exactly solvable model in quantum mechanics that describes the propagation of particles through a potential field created by regularly spaced $\delta'$-type point interactions, which model the localized dipoles often observed in crystal structures. We refer to the corresponding potentials as $\delta'_\theta$-combs, where the parameter $\theta$ represents the contrast of the resonant wave at zero energy and determines the interface conditions in the Hamiltonians. We explicitly calculate the scattering matrix for these systems and prove that the transmission probability exhibits sharp resonance peaks while rapidly decaying at other frequencies. Consequently, Hamiltonians with $\delta'_\theta$-comb potentials act as quantum filters, permitting tunnelling only for specific wave frequencies. Furthermore, for each $\theta > 0$, we construct a family of regularized Hamiltonians approximating the ideal model and prove that their transmission probabilities have a similar structure, thereby confirming the physical realizability of the band-pass filtering effect.

Quantum state engineering of light using intensity measurements and post-selection

2025-06-24

NULL AUTHOR_ID | Physical review. A/Physical review, A

Symmetry-protected topological optical lattice clock

2025-06-24

NULL AUTHOR_ID | PRX Quantum

Observation of anomalous light localization in periodic moiré lattices with large lattice constants

2025-06-23

Qingying Quan , Zihan Liu , Biao Yan +2 more | Optics Letters

Correlated-hopping-induced topological order in an atomic mixture

2025-06-23

NULL AUTHOR_ID | Physical review. A/Physical review, A

Utilization of a Dual-Layer Graphene Structure for Slow Light Engineering in the Terahertz Band

2025-06-20

Abolfazl Vaghayei , Majid Afsahi , Mohammad Danaie | Research Square (Research Square)

<title>Abstract</title> The proposed structure comprises a unit cell with two dielectric substrates: SiO2 and nine graphene disks, positioned on the lower substrate. Additionally, a square patch of graphene is situated … <title>Abstract</title> The proposed structure comprises a unit cell with two dielectric substrates: SiO2 and nine graphene disks, positioned on the lower substrate. Additionally, a square patch of graphene is situated on the upper substrate. The conductive behavior of graphene at terahertz frequencies is described using a specialized model. The impedance and electrical characteristics of this structure are modeled through RLC relationships, and simulations have been conducted to analyze the interaction of terahertz waves with the structure. The results indicate that the Fermi energy of graphene can influence the resonance frequency of the structure, leading to variations in optical properties such as group delay and group velocity. Overall, the findings of this research highlight the potential for optical control and tuning in the terahertz band utilizing graphene and its metamaterials, presenting strategic capabilities for telecommunications and photonic applications.

Time-reversed Landau-Zener tunneling in synthetic temporal lattices

2025-06-20

NULL AUTHOR_ID | Physical review. A/Physical review, A

Comparison of Different Rydberg Atom-Based Microwave Electrometry Techniques

2025-06-20

Emanuel Eliabe Alves , Manuel Alejandro Lefrán Torres , J. Kondo +1 more | Atoms

In this study, we have compared different Rydberg atom-based microwave electrometry techniques under the same experimental conditions and using the same Rydberg states (68S1/2, 68P3/2, and 67P3/2). The comparison was … In this study, we have compared different Rydberg atom-based microwave electrometry techniques under the same experimental conditions and using the same Rydberg states (68S1/2, 68P3/2, and 67P3/2). The comparison was carried out for the following techniques: (i) auxiliary microwave field, (ii) microwave amplitude modulation, and (iii) polarization spectroscopy. Our results indicate that all three techniques have a similar minimum measurable microwave electric field. A slightly better result can be obtained by performing polarization spectroscopy using a Laguerre–Gauss coupling laser beam.

Feasibility Study of Multistage Low‐Pass NGD Circuit Design Methodology Using RL‐Network

2025-06-18

Yujie Chen , Lu Jianing , Sonia Moussa +4 more | International Journal of Circuit Theory and Applications

ABSTRACT The negative group delay (NGD) circuit is uniquely capable of propagating arbitrary waveform signals with time advancement. Achieving significant NGD performance in practical applications, however, requires a multistage design … ABSTRACT The negative group delay (NGD) circuit is uniquely capable of propagating arbitrary waveform signals with time advancement. Achieving significant NGD performance in practical applications, however, requires a multistage design approach. This article develops a design methodology for multistage low‐pass (LP) NGD circuits based on RL‐networks. After recalling the theoretical design equations enabling the determination of the multistage LP‐NGD parameters based on the desired time advance and signal bandwidth, a design flow methodology is introduced. As proof‐of‐concept, a feasibility study of a multistage LP‐NGD circuit, designed for a time advance of −100 ms, is conducted using a three‐stage printed circuit board (PCB) consisting of RL‐cells. Simulations in both the frequency and time domains confirm that the fabricated PCB prototype can propagate different waveform signals as expected, demonstrating the LP‐NGD properties. Time‐advance measurements with the PCB prototype further validate these LP‐NGD effect findings. The proposed multistage design methodology provides a promising solution for addressing signal delay issues and offers new opportunities for innovative signal processing applications in future electronic systems.

Classical-quantum scattering

2025-06-17

Daniel Carney , Akira Matsumura | Classical and Quantum Gravity

Abstract We analyze the framework recently proposed by Oppenheim et al. [Nat. Comm. \textbf{14} no.1, (2023), Phys. Rev. X 13 (2023) 041040, arXiv:2302.07283 [gr-qc], JHEP 08 (2023) 163] to model … Abstract We analyze the framework recently proposed by Oppenheim et al. [Nat. Comm. \textbf{14} no.1, (2023), Phys. Rev. X 13 (2023) 041040, arXiv:2302.07283 [gr-qc], JHEP 08 (2023) 163] to model relativistic quantum fields coupled to relativistic, classical, stochastic fields (in particular, as a model of quantum matter coupled to “classical gravity”). Perhaps surprisingly, we find that we can define and calculate scattering probabilities which are Lorentz-covariant and conserve total probability, at least at tree level. As a concrete example, we analyze 2 → 2 scattering of quantum matter mediated by a classical Yukawa field. Mapping this to a gravitational coupling in the non-relativistic limit, and assuming that we can treat large objects as point masses, we find that the simplest possible “classical-quantum” gravity theory constructed this way gives predictions for 2 → 2 gravitational scattering which are inconsistent with simple observations of, e.g., spacecraft undergoing slingshot maneuvers. We comment on lessons learned for attempts to couple quantum matter to “non-quantum” gravity, or more generally, for attempts to couple relativistic quantum and classical systems.

Superluminal and tunnelling solutions to Maxwell equations from the perspective of classical electrodynamics

2025-06-17

Luca Nanni | Indian Journal of Physics

Enhanced control of the Goos–Hänchen shift at graphene-hyperbolic boron nitride multilayer hyper crystal

2025-06-17

Kishwar Ali , Francesco Ferranti , Fabrizio Frezza +1 more | Optics & Laser Technology

Nonreciprocal cavity induced by chiral broadening

2025-06-16

Lifeng Liu , Yueping Niu , Shangqing Gong | Applied Physics Letters

Creating nonreciprocal optical components is important for applications such as optical communication, quantum networks, and emerging applications in artificial intelligence and machine learning. In particular, ring cavities with nonreciprocal clockwise … Creating nonreciprocal optical components is important for applications such as optical communication, quantum networks, and emerging applications in artificial intelligence and machine learning. In particular, ring cavities with nonreciprocal clockwise (CW) and counterclockwise (CCW) modes play essential roles in quantum nonreciprocity, sensing, and in-memory photonic computing cells. Here, we propose a scheme to realize magnetic-free nonreciprocal cavity modes in a stationary cavity by using the natural chiral broadening hiding in the thermal atomic ensemble. The chiral broadening causes different phase delays for the CW and CCW modes, resulting in a difference in their resonant frequencies, which supports the breaking of their degeneracy. It is found that this difference is proportional to atomic density and interaction length. We experimentally demonstrate such a nonreciprocal cavity and get higher than 98% isolation contrast as an isolator. Since the difference required for these two cavity modes to be completely separated depends on the cavity linewidth, the requirement of atomic density and interaction length in our scheme can be dramatically reduced by increasing the finesse of the cavity, which paves the way for miniaturization and integration of such a nonreciprocal component. Moreover, nonreciprocal cavity modes serve as a chiral reservoir, enabling the exploration of physics driven by this chirality.

Goos-Hänchen shift and photonic spin Hall effect in semi-Dirac material heterostructures

2025-06-16

NULL AUTHOR_ID | Physical review. A/Physical review, A

Numerical realization of tunable triple-band slow wave and bidirectional rainbow trapping in magneto-optical heterostructures

2025-06-16

Mengting Yang , Yun You , Yu-Tang Luo +4 more | Optics Express

Composite asymmetric dark matter with a dark photon portal: Multimessenger tests

2025-06-14

NULL AUTHOR_ID | Physical review. D/Physical review. D.

Influence of nonlinearity and Doppler effect on group index in a four-level tripod atom system

2025-06-14

Nguyen Huy Bang , Le Nguyen Mai Anh , Luong Thi Yen Nga +4 more | Chaos Solitons & Fractals

Quantum non-Gaussian coherences of an oscillating atom

2025-06-13

NULL AUTHOR_ID | Physical Review Research

Quantum-optical scattering by macroscopic lossy objects: A general approach

2025-06-13

NULL AUTHOR_ID | Physical review. A/Physical review, A

A Platform for All-Optical Thomson/Compton Scattering with Versatile Parameters

2025-06-13

Li-Ming Chen , Wenchao Yan , Mingyang Zhu +7 more | High Power Laser Science and Engineering

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Nonsecular thermalization dynamics of multilevel quantum systems: Complete positivity and insights from Kossakowski matrix spectra

2025-06-12

NULL AUTHOR_ID | Physical review. A/Physical review, A

Asymmetric Biphoton Generation under Ground‐State Decoherence and Phase Mismatch in a Cold Atomic Ensemble

2025-06-11

Jiun‐Shiuan Shiu , Chang‐Wei Lin , Yong‐Fan Chen | Advanced Quantum Technologies

Abstract An experimental investigation of how ground‐state decoherence and phase mismatch influence biphoton generation in double‐Λ spontaneous four‐wave mixing (SFWM) within a cold atomic ensemble is presented. The results reveal … Abstract An experimental investigation of how ground‐state decoherence and phase mismatch influence biphoton generation in double‐Λ spontaneous four‐wave mixing (SFWM) within a cold atomic ensemble is presented. The results reveal significant asymmetry in the Stokes and anti‐Stokes photon generation rates, arising from the distinct effects of phase mismatch and ground‐state decoherence. While phase mismatch primarily drives this asymmetry under minimal decoherence, larger decoherence further amplifies it, underscoring the complex interplay between these factors. Using the coincidence count rate representation, insights are provided into pairing ratios, demonstrating that the stimulated four‐wave mixing process inherent in SFWM explains the observed phenomena. Interestingly, although ground‐state decoherence reduces the generation of temporally correlated photons, it paradoxically enhances biphoton purity, as confirmed through conditional autocorrelation measurements. This counterintuitive phenomenon is reported here for the first time. Furthermore, unconditional autocorrelation measurements show that the generated photons follow a thermal‐state distribution, consistent with theoretical predictions. This study advances the understanding of biphoton generation dynamics and temporal photon correlations in SFWM, offering valuable insights for optimizing SFWM‐based biphoton sources and their applications in quantum technologies.

Controlling dephasing of coupled qubits via shared bath coherence

2025-06-09

NULL AUTHOR_ID | Physical review. B./Physical review. B

Goos-Hänchen shift in two-dimensional hexagonal materials

2025-06-06

Bilal Rashid , Madeeha Shabnam , A. Alqahtani | Journal of Physics D Applied Physics

Abstract In this study, we examined the Goos-Hänchen (GH) shift of light beams reflected from the surfaces of various two-dimensional (2D) hexagonal materials. We employed a generalized Hamiltonian to analytically … Abstract In this study, we examined the Goos-Hänchen (GH) shift of light beams reflected from the surfaces of various two-dimensional (2D) hexagonal materials. We employed a generalized Hamiltonian to analytically derive the band structures, longitudinal, and Hall conductivities of these materials. By manipulating the interaction between external electric fields and spin-orbit coupling, we demonstrated that topological phase transitions can be induced in buckled Xene monolayers, which can be probed through the GH shift. The GH shift exhibits distinct behaviors across different topological phases in these materials, providing valuable insights into their unique characteristics. Additionally, we investigated the valley- and spin-polarized spatial and angular GH shifts in monolayer transition-metal dichalcogenides (ML-TMDCs) upon reflection. We found that both lateral and angular shifts in these materials, as well as in buckled silicene monolayers, are strongly influenced by spin and valley degrees of freedom. This sensitivity makes the GH shift a promising tool for advancing research in spintronics and valleytronics.