Dissipative solitons and vortices in polariton Bose-Einstein condensates

Abstract

We examine spatial localisation and dynamical stability of Bose-Einstein condensates of excitonpolaritons in microcavities under the condition of off-resonant spatially inhomogeneous optical pumping both with and without a harmonic trapping potential. We employ the open-dissipative Gross-Pitaevskii model for describing an incoherently pumped polariton condensate coupled to an exciton reservoir, and reveal that spatial localisation of the steady-state condensate occurs due to the effective self-trapping created by the polariton flows supported by the spatially inhomogeneous pump, regardless of the presence of the external potential. A ground state of the polariton condensate with repulsive interactions between the quasiparticles represents a dynamically stable bright dissipative soliton. We also investigate the conditions for sustaining spatially localised structures with non-zero angular momentum in the form of single-charge vortices.

Bosonic lasers: The state of the art (Review Article)

“…Experiments with Mexican hat shaped profiles showed how it was possible to trap vortex-antivortex pairs [50]. The optical trapping of polaritons can also be achieved based on the balances between optically controlled gain and loss [51], providing a mechanism for dissipative solitons [33].…”

“…The resulting coherent state of polaritons is well described by a nonlinear Schrödinger equation (also known as a Gross-Pitaevskii equation), modified to account for gain and loss in the system [30]. Theoretical studies revealed that this equation supports a variety of spatially nontrivial structures, including: vortices and vortex lattices [31,32]; solitons [33][34][35][36][37]; and various other patterns [38][39][40].…”

Localization and self-trapping in driven-dissipative polariton condensates

“…For larger γ > J = 1 the transition is instead from the normal state to an asymmetrical-density condensate and follows the boundary given by Eq. (17). The continuation of this curve into the region γ < J does not correspond to a phase boundary: The solution which crosses zero density with increasing g or γ in this region, and so becomes physical, does not become stable.…”

“…Such oscillations also occur in the dissipationdominated regime, where they reflect the coexistence of two condensates of different frequencies, as in a multimode laser [19]. Indeed at the qualitative level many important phenomena, like gap solitons [14,15], vortices [16], and condensate localization [17,24,25], occur in both interaction-dominated and dissipation-dominated condensates.…”

“…In this direction, advances in fabrication have led to successful demonstrations of Josephson oscillations as well as self-trapping in micropillar cavities [12,13]. The interplay between interactions and coherence, central to such phenomena, also has an important role in the formation of localized structures such as gap solitons [14,15] and vortices [16,17].…”