Multimode-polariton superradiance via Floquet engineering

Abstract

We consider an ensemble of ultracold bosonic atoms within a near-planar cavity, driven by a far detuned laser whose phase is modulated at a frequency comparable to the transverse cavity mode spacing. We show that a strong, dispersive atom-photon coupling can be reached for many transverse cavity modes at once. The resulting Floquet polaritons involve a superposition of a set of cavity modes with a density excitation of the atomic cloud. The mutual interactions between these modes lead to distinct avoided crossings between the polaritons. Increasing the laser drive intensity, a low-lying multimode Floquet polariton softens and eventually becomes undamped, corresponding to the transition to a superradiant, self-organized phase. We demonstrate the stability of the stationary state for a broad range of parameters.

Floquet engineering of non-equilibrium superradiance

“…It has been shown that population inversion of Floquet states can occur in driven systems [39][40][41]. Floquet theory itself presents a method to describe the effective dressed states in driven systems and their population, and is applicable to driven dissipative cavity systems [42,43], in particular.…”

Floquet Engineering of Non-Equilibrium Superradiance

“…Floquet theory itself presents a method to describe the effective dressed states in driven systems and their population, and is in particular also applicable to driven dissipative cavity systems [36,37]. We present the emergence of a Floquet-assisted superradiant phase (FSP) in the dissipative Dicke model under the influence of circularly polarized driving of the two-level systems, reminiscent of the Rabi model.…”