Opening a gap in the dispersion of the collective excitations of a driven-dissipative condensate subject to an external coherent drive
Year: 2026
Authors: Stazzu E., Sacchetto G.A.P., Carusotto I.
Autors Affiliation: Univ Trento, Pitaevskii BEC Ctr, CNR INO, Via Sommar 14, I-38123 Trento, Italy; Univ Trento, Dipartimento Fis, Via Sommar 14, I-38123 Trento, Italy.
Abstract: We build a minimal theoretical model to describe the opening of a gap in the dispersion of the collective excitations of a driven-dissipative condensate when the condensate phase is fixed by an additional coherent phase-locking drive. We map out the phase diagram as a function of the amplitude and frequency of the coherent drive, identifying distinct regions corresponding to different steady-state regimes. For each region, we analyze the dispersion of the collective excitations and determine whether the spectrum is gapped, with either a purely imaginary gap or a finite real part. When the coherent drive is unable to lock the condensate phase, a gapless Goldstone mode is recovered. Within the same phase diagram, we further identify regions of finite-wave-vector dynamical instability, where the condensate tends to develop a supersolid-like spatial modulation. While our theoretical framework is directly related to recent experiments with exciton-polariton condensates, it can be applied to describe the effect of external injection also in a variety of spatially extended optical parametric oscillators or laser devices.
Journal/Review: PHYSICAL REVIEW A
Volume: 113 (5) Pages from: 53303-1 to: 53303-14
More Information: I.C. acknowledges continuous exchanges with Alberto Bramati and Michiel Wouters, as well as financial sup-port from Provincia Autonoma di Trento (PAT) , the Q@TN Initiative, and the National Quantum Science and Technology Institute through the PNRR MUR project under Grant No. PE0000023-NQSTI, cofunded by the European Union- NextGeneration EU.KeyWords: Injection; LockingDOI: 10.1103/5kr9-ry4f
