Complex spatial structures due to atomic coherence

Oppo, Gian-Luca

doi:10.1080/09500341003774704

Cited by 14 publications

(16 citation statements)

References 44 publications

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“…Details of these structures and the transition to squares via magnetic field and intensity are currently under investigation. Some theoretical papers considered the possibility of coherence based self-organized states in cavities [133,134], but we are not aware of any previous experiment before Ref. [51] demonstrating self-organized coherences.…”

Section: Quadrupole Structuresmentioning

confidence: 98%

Self-Organization in Cold Atoms Mediated by Diffractive Coupling

Ackemann

Labeyrie

Baio

et al. 2021

Atoms

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This article discusses self-organization in cold atoms via light-mediated interactions induced by feedback from a single retro-reflecting mirror. Diffractive dephasing between the pump beam and the spontaneous sidebands selects the lattice period. Spontaneous breaking of the rotational and translational symmetry occur in the 2D plane transverse to the pump. We elucidate how diffractive ripples couple sites on the self-induced atomic lattice. The nonlinear phase shift of the atomic cloud imprinted onto the optical beam is the parameter determining coupling strength. The interaction can be tailored to operate either on external degrees of freedom leading to atomic crystallization for thermal atoms and supersolids for a quantum degenerate gas, or on internal degrees of freedom like populations of the excited state or Zeeman sublevels. Using the light polarization degrees of freedom on the Poincaré sphere (helicity and polarization direction), specific irreducible tensor components of the atomic Zeeman states can be coupled leading to spontaneous magnetic ordering of states of dipolar and quadrupolar nature. The requirements for critical interaction strength are compared for the different situations. Connections and extensions to longitudinally pumped cavities, counterpropagating beam schemes and the CARL instability are discussed.

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Section: Quadrupole Structuresmentioning

confidence: 98%

Self-Organization in Cold Atoms Mediated by Diffractive Coupling

Ackemann

Labeyrie

Baio

et al. 2021

Atoms

Self Cite

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“…Equation (1) is a generalization of the model introduced in Ref. [10] since in the evaluation of ρ 13 we used a less stringent condition of | | 2 |E 2 | 2 instead of | | |E 2 | 2 . The bistable nature of the light-atom interaction and the capability of the system for displaying EIT in the present model (1) are extended to a wider parameter space than that of [10] [see, for example, Figs.…”

Section: The Modelmentioning

confidence: 99%

“…The complex spatial structures forming in nonlinear cavities displaying electromagnetically induced transparency (EIT) [10] show generalized multistability of the kind described above. In particular, it will be shown that different spatially periodic structures (optical patterns) are obtained for different initial conditions but the same parameter values.…”

Section: Introductionmentioning

confidence: 98%

Complex structures in media displaying electromagnetically induced transparency: Pattern multistability and competition

et al. 2014

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Spatially periodic and localized structures in the transverse plane of a medium displaying electromagnetically induced transparency in an optical cavity and under the action of two pumps are investigated. The system supports a multitude of different complex spatial structures depending on the chosen initial condition. We explore regimes of multistable patterns, filaments, stable defects, scrolling structures, nested patterns, fronts, and the spontaneous occurrence of multiple cavity solitons. To simulate realistic conditions of operation, we replace periodic boundary conditions with pumps of finite size. Many of the multistable features are recovered apart from the scrolling of patterns with defects.

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“…All fields E, E I and E 2 are normalized to the square root of the saturation intensity of the first atomic transition. θ is the detuning between the cavity resonance and the frequency of the injected pump beam normalized to the inverse of the photon lifetime, and ρ 13 is the off-diagonal density matrix element proportional to the field amplitude E and the complex susceptibility χ via the relation [36,37]:…”

Section: The Modelmentioning

confidence: 99%

Complex structures in cavities with media displaying EIT: coexistence, defects and selection mechanism

Eslami

Kheradmand

Oppo

2020

J. Phys. B: At. Mol. Opt. Phys.

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A cavity filled with a medium displaying electromagnetically induced transparency is shown to exhibit coexistence of complex transverse structures often leading to pattern competition. Because of multi-stability of the solutions, the asymptotic state in such a cavity crucially depends on the values of the control parameters and the initial conditions. The pattern competition can result in coexisting regions of pattern structures of different geometry separated by stable or metastable fronts. Here we propose a selection technique based on external periodic modulations for directing the system to a single pattern state of choice and thus removing the separation fronts. The control technique takes the system close to subsections in the phase space providing the operator with the choice of the final state from different multi-stable solutions. We extend the use of the technique to stationary or drifting structures composed of regions made of a single pattern state with different orientations. In this case the regularization to a pattern with a single orientation is associated with the removal of defects. The harmonic signal technique has not been used previously to control a spatio-temporal system where the multi-stability is due to the coupling of nonlinearity and diffraction.

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Complex spatial structures due to atomic coherence

Cited by 14 publications

References 44 publications

Self-Organization in Cold Atoms Mediated by Diffractive Coupling

Self-Organization in Cold Atoms Mediated by Diffractive Coupling

Complex structures in media displaying electromagnetically induced transparency: Pattern multistability and competition

Complex structures in cavities with media displaying EIT: coexistence, defects and selection mechanism

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