Collective spontaneous emission from a line of atoms

Clemens, James; Horvath, L.; Sanders, Barry C.; Carmichael, H. J.

doi:10.1103/physreva.68.023809

Cited by 119 publications

(113 citation statements)

References 31 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…These methods, whether called classicalelectrodynamics simulations or coupled-dipole simulations, are now a routine theoretical tool [2,4,7,8,[14][15][16][17][18][19][20][21][22][23][24][25][26]. Closely related numerical techniques based on the analysis of the eigenstates of the coupled system of the light and the atoms [15,[27][28][29][30][31][32] or density matrices and quantum trajectories [33][34][35] are also widely used today. Other ideas drawn from the theory of radiative transfer [36,37] and multiple scattering [38,39], enhanced with numerics, also have potential to make inroads into the questions about light propagation in atomic media [40].…”

Section: Introductionmentioning

confidence: 99%

Exact electrodynamics versus standard optics for a slab of cold dense gas

Javanainen

Ruostekoski

et al. 2017

Phys. Rev. A

View full text Add to dashboard Cite

We study light propagation through a slab of cold gas using both the standard electrodynamics of polarizable media and massive atom-by-atom simulations of the electrodynamics. The main finding is that the predictions from the two methods may differ qualitatively when the density of the atomic sample ρ and the wave number of resonant light k satisfy ρk −3 1. The reason is that the standard electrodynamics is a mean-field theory, whereas for sufficiently strong light-mediated dipole-dipole interactions the atomic sample becomes strongly correlated. The deviations from mean-field theory appear to scale with the parameter ρk −3 , and we demonstrate noticeable effects already at ρk −3 10 −2 . In dilute gases and in gases with an added inhomogeneous broadening the simulations show shifts of the resonance lines in qualitative agreement with the predicted Lorentz-Lorenz shift and "cooperative Lamb shift," but the quantitative agreement is unsatisfactory. Our interpretation is that the microscopic basis for the local-field corrections in electrodynamics is not fully understood.

show abstract

Section: Introductionmentioning

confidence: 99%

Exact electrodynamics versus standard optics for a slab of cold dense gas

Javanainen

Ruostekoski

et al. 2017

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…To explore these collective effects, many new ideas, such as the quantum jump approach, were developed to treat superradiance [16,17,18]. Recently, we successfully incorporated cooperative effects into a novel formalism for optically dense media.…”

mentioning

confidence: 99%

Superradiance in ultracold Rydberg gases

et al. 2007

View full text Add to dashboard Cite

Experiments in dense, ultracold gases of rubidium Rydberg atoms show a considerable decrease of the radiative excited state lifetimes compared to dilute gases. This accelerated decay is explained by collective and cooperative effects, leading to superradiance. A novel formalism to calculate effective decay times in a dense Rydberg gas shows that for these atoms the decay into nearby levels increases by up to three orders of magnitude. Excellent agreement between theory and experiment follows from this treatment of Rydberg decay behavior.In recent years, ultracold atomic gases have been used to probe a variety of many-body phenomena such as Bose-Einstein condensation [1,2] and degenerate Fermi gases [3]. In addition to collective effects due to particle statistics, other manifestations of many-body physics have been explored, such as in slow-light experiments [4] and in ultracold Rydberg gases (e.g. the diffusion of excitations through resonant collisions [5] and the blockade mechanism [6]). Another important fundamental collective effect is superradiance, in which photon exchange between atoms modifies the behavior of the sample. In particular, cooperative effects due to virtual photon exchange can lead to the formation of so called Dicke states [7]. These states are the symmetric superposition of all states with the same total excitation level for constant atom number N . Interest in Dicke states has grown recently because of their potential advantages in quantum information processing [8] and their importance in the behavior of Bose-Einstein condensates [9].In this Letter, we are interested in many-body physics involving photon exchange in an ultracold gas of Rydberg atoms. Because superradiance depends on the atomic density per cubic wavelength, and because radiative decay of Rydberg atoms takes place predominantly between the closely spaced upper levels, ultracold Rydberg gases are ideal systems to study superradiance. In fact, Rydberg atoms have many interesting properties: their size can become comparable to the atomic separation, and they have huge dipole moments ℘ ∼ n 2 , where n is the principal quantum number of the Rydberg state. In addition, for long-wavelength transitions between neighboring states of high n the "cooperative parameter" C = N λ 3 /4π 2 (where N is the density of atoms, λ is the transition wavelength), is large for Rydberg atoms, which means collective effects are much easier to obtain than for ground-state atoms [10]. This was confirmed in earlier experiments for Rydberg atoms at high [11,12] and low temperatures [13]. Note that these many-body effects may pose a limit on the measurement of lifetimes of Rydberg atoms [14] and may cause undesirable frequency shifts, for example in atomic clocks [15].The source responsible for both virtual and real photon exchange is the dipole-dipole interaction. It governs the build-up as well as the decay of coherence in a dense radiating sample. On the one hand, the virtual exchange of photons is responsible for the so-called exchange interaction. ...

show abstract

“…It was originally introduced by Dicke in his famous article published in 1954, and currently a very large literature exists on a wide variety of problems involving the model, in particular on the concepts of super-radiance and the directional propagation of light in atomic ensembles [79][80][81]. Recently, the model has been employed in the studies of entanglement, in particular for creation of entanglement in atomic ensembles composed of a large number of trapped and cooled atoms [41][42][43]45].…”

Section: B the Dicke Modelmentioning

confidence: 99%

Quantum entanglement and disentanglement of multi-atom systems

Ficek

2009

Front. Phys. China

View full text Add to dashboard Cite

We present a review of recent research on quantum entanglement, with special emphasis on entanglement between single atoms, processing of an encoded entanglement and its temporary evolution. Analysis based on the density matrix formalism are described. We give a simple description of the entangling procedure and explore the role of the environment in creation of entanglement and in disentanglement of atomic systems. A particular process we will focus on is spontaneous emission, usually recognized as an irreversible loss of information and entanglement encoded in the internal states of the system. We illustrate some certain circumstances where this irreversible process can in fact induce entanglement between separated systems. We also show how spontaneous emission reveals a competition between the Bell states of a two qubit system that leads to the recently discovered "sudden" features in the temporal evolution of entanglement. An another problem illustrated in details is a deterministic preparation of atoms and atomic ensembles in long-lived stationary squeezed states and entangled cluster states. We then determine how to trigger the evolution of the stable entanglement and also address the issue of a steered evolution of entanglement between desired pairs of qubits that can be achieved simply by varying the parameters of a given system.

show abstract

Collective spontaneous emission from a line of atoms

Cited by 119 publications

References 31 publications

Exact electrodynamics versus standard optics for a slab of cold dense gas

Exact electrodynamics versus standard optics for a slab of cold dense gas

Superradiance in ultracold Rydberg gases

Quantum entanglement and disentanglement of multi-atom systems

Contact Info

Product

Resources

About