Properties of the signal mode in the polariton optical parametric oscillator regime

Abstract

Theoretical analyses of the polariton optical parametric oscillator (OPO) regime often rely on a mean field approach based on the complex Gross-Pitaevskii equations in a three-mode approximation, where only three momentum states, the signal, pump and idler, are assumed to be significantly occupied. This approximation, however, lacks a constraint to uniquely determine the signal and idler momenta. In contrast, multimode numerical simulations and experiments show a unique momentum structure for the OPO states. In this work we show that an estimate for the signal momentum chosen by the system can be found from a simple analysis of the pump-only configuration. We use this estimate to investigate how the chosen signal momentum depends on the properties of the drive. arXiv:1804.10129v3 [cond-mat.quant-gas]

Kibble-Zurek Mechanism in Driven Dissipative Systems Crossing a Nonequilibrium Phase Transition

“…Testing the KZ mechanism.-First, we need to numerically determine the crossover timet num from the vortex dynamics during a finite-speed ramp. The number of vortices across the Berezinskii-Kosterlitz-Thouless transition at steady state is known to decrease gradually as the transition is approached from the disordered side and to exhibit a sharp decrease in a narrow region around the critical point, as already analyzed for OPO polaritons in [48,52,64]. This feature, in combination with a simultaneous study of the spatial correlation function is used to precisely locate the critical point.…”

“…Polariton phase transition and modeling.-As discussed in the literature on spontaneous macroscopic coherence and the nonequilibrium condensation phase transition of polaritons [32,48,[50][51][52][53]64,65], both the OPO and the IP polariton systems show rich yet qualitatively very similar phase diagrams, with two main distinct phases: (i) a disordered phase displaying a low density of polaritons, an exponential decay of spatial correlations and a plasma of unbound vortices and (ii) a (quasi)ordered phase displaying a significant density of polaritons, an algebraic decay of spatial correlations (at least up to relatively long distances [39,52,54]), and a low density of vortices, mostly bound in vortex-antivortex pairs [48,52,65].…”

Bistability and nonequilibrium condensation in a driven-dissipative Josephson array: a c-field model

“…Our system corresponds to the case of anomalous dispersion α < 0, defocussing nonlinearity β > 0, and blue-detuned driving Ω > 0; however, all of these may in general be of either sign [35] depending on the physical system. The LLE and generalized versions also arise in the context of superfluid excitonpolariton systems with coherent pumping [28,[37][38][39][40][41][42].…”

Loop parametric scattering of cavity polaritons

“…This analogy is not perfect because the polariton system never comes to a state with only three nonempty wave modes [13][14][15]. Nevertheless, the condensate induced by coherent pumping usually remains the most populated mode that governs all signals and idlers excited owing to the parametric scattering [16][17][18][19].…”