Collective resonance fluorescence in small and dense atom clouds: Comparison between theory and experiment

Jenkins, S. D.; Ruostekoski, Janne; Javanainen, Juha; Jennewein, Stephan; Bourgain, Ronan; Pellegrino, Joseph G.; Sortais, Yvan R. P.; Browaeys, Antoine

doi:10.1103/physreva.94.023842

Cited by 81 publications

(61 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The absence of the LL shift has since been demonstrated in light scattering experiments from a small and dense trapped cloud of atoms [2,7,53]. These experiments were about sideways scattering, however, which does not directly belong to the MFT framework.…”

Section: Discussionmentioning

confidence: 99%

“…However, the exact opposite holds true: For a fixed detuning and hence fixed polarizability α, E(r ± ) actually tend to zero as 3 when the distance between the dipoles tends to zero. Maybe counterintuitively, when the detuning is kept constant and the atoms approach each other, they decouple from the light altogether [53]. That is why we are not overly concerned about some atoms being close to one another in the steady-state numerical simulations.…”

Section: B Radiation From Two Atomsmentioning

confidence: 99%

“…This isotropy is because of our underlying assumption of the J g = 0 → J e = 1 transition. However, for other types of transitions [53] the appropriate polarization tensor α ij could be defined such that the relation between the vector components of the dipole moment and the electric field reads d i = j α ij E j .…”

Section: B Classical-electrodynamics Solution For Light Propagationmentioning

confidence: 99%

See 2 more Smart Citations

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: Discussionmentioning

confidence: 99%

Section: B Radiation From Two Atomsmentioning

confidence: 99%

Section: B Classical-electrodynamics Solution For Light Propagationmentioning

confidence: 99%

See 1 more Smart Citation

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

“…Note that approaches similar to those described in this paper are used to analyze the atomic decay or dynamics of fluorescence in several works [21]- [35]. In the main part of the mentioned references, the scalar approximation was used.…”

Section: Basic Assumptions and Approachmentioning

confidence: 99%

Angular distribution of single-photon superradiance in a dilute and cold atomic ensemble

2017

View full text Add to dashboard Cite

On the basis of a quantum microscopic approach we study the dynamics of the afterglow of a dilute Gaussian atomic ensemble excited by pulsed radiation. Taking into account the vector nature of the electromagnetic field we analyze in detail the angular and polarization distribution of single-photon superradiance of a such ensemble. The dependence of the angular distribution of superradiance on the length of the pulse and its carrier frequency as well as on the size and the shape of the atomic clouds is studied. We show that there is substantial dependence of the superradiant emission on the polarization and the direction of fluorescence. We observe essential peculiarities of superradiance in the region of the forward diffraction zone and in the area of the coherent backscattering cone. We demonstrate that there are directions for which the rate of fluorescence is several times more than the decay rate of the timed-Dicke state. We show also that single-photon superradiance can be excited by incoherent excitation when atomic polarization in the ensemble is absent. Besides a quantum microscopic approach, we analyze single-photon superradiance on the basis of the theory of incoherent multiple scattering in optically thick media (random walk theory). In the case of very short resonant and long nonresonant pulses we derive simple analytical expressions for the decay rate of single-photon superradiance for incoherent fluorescence in an arbitrary direction.

show abstract

“…Collective scattering of a weakintensity laser off a cold ensemble of rubidium atoms with Zeeman splitting has been recently investigated both theoretically and experimentally [16][17][18][19], with results that partly contradict predictions of the standard cooperative Lamb shift theory. In the context of ensembles of atoms in magnetic fields, a legitimate question is to which extend can the Zeeman splitting be considered independently from the cooperative effects and in particular the collective Lamb shift.…”

mentioning

confidence: 99%

Collective radiation spectrum for ensembles with Zeeman splitting in single-photon superradiance

Kong

Pálffy

2017

Phys. Rev. A

View full text Add to dashboard Cite

In an ensemble of identical atoms, cooperative effects like sub-or superradiance may alter the decay rates and the energy of specific transitions may be shifted from the single-atom value by the so-called collective Lamb shift. While such effects in ensembles of two-level systems are by now well understood, realistic multi-level systems are more difficult to handle. In this work we show that in a system of atoms or nuclei under the action of an external magnetic field, the collective contribution to the level shifts can amount to seizable deviations from the single-atom Zeeman or magnetic hyperfine splitting picture. We develop a formalism to describe single-photon superradiance in multi-level systems in the small sample limit and quantify the parameter regime for which the collective Lamb shift leads to measurable deviations in the magnetic-field-induced splitting. In particular, we show that this effect should be observable in the nuclear magnetic hyperfine splitting in Mössbauer nuclei embedded in thin-film x-ray cavities. PACS numbers: 78.70.Ck, 42.50.Nn, 76.80.+y 32.30.Dx In 1947, a famous experiment by Lamb and Retherford [1] confirmed that the 2s 1/2 and 2p 1/2 levels in hydrogen are not degenerate, leading to increased efforts in the theoretical understanding of radiation quantization [2,3] and to the development of quantum electrodynamics (QED) [4]. Today, it is known that this small shift has to do with emission and reabsorption of virtual photons within the atom, mainly with selfenergy and vacuum-polarization corrections. Interestingly, it could be shown that an additional contribution arises if many identical atoms are interacting collectively with resonant photons, and virtual photons are exchanged between different atoms [5][6][7][8][9][10]. This additional contribution has been termed in analogy collective Lamb shift, although the exact underlying processes share with the single-atom Lamb shift mechanism only the virtual character of the photons being exchanged.The collective Lamb shift has been investigated theoretically for ensembles of two-level systems in the small and large sample limits [5,[11][12][13][14][15]. Collective scattering of a weakintensity laser off a cold ensemble of rubidium atoms with Zeeman splitting has been recently investigated both theoretically and experimentally [16][17][18][19], with results that partly contradict predictions of the standard cooperative Lamb shift theory. In the context of ensembles of atoms in magnetic fields, a legitimate question is to which extend can the Zeeman splitting be considered independently from the cooperative effects and in particular the collective Lamb shift. In this Letter, we show that in ensembles of atoms or nuclei with magneticfield induced level multiplets, the collective magnetic splitting can show significant deviations of the Zeeman splitting compared to the single-atom behaviour and cannot be justified by mere two-level system collective Lamb shift contributions for each transition independently, as done for instance in Re...

show abstract

Collective resonance fluorescence in small and dense atom clouds: Comparison between theory and experiment

Cited by 81 publications

References 61 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

Angular distribution of single-photon superradiance in a dilute and cold atomic ensemble

Collective radiation spectrum for ensembles with Zeeman splitting in single-photon superradiance

Contact Info

Product

Resources

About