Phase transition, phase separation and mode softening of a two-component Bose-Einstein condensate in an optical cavity

Abstract

We investigate the superradiant phase transition in a two-component Bose-Einstein condensate with distinct atomic detunings, confined in an optical cavity and driven by a transverse pump laser. By combining perturbation theory and numerical simulations, we demonstrate that the phase transition is dominated by the red-detuned component, resulting in a phase diagram completely different from that of a single-component case under blue-detuned condition. The system exhibits spontaneous phase separation between the two components, manifested as alternating stripe patterns in the normal phase and distinct Bragg gratings in the superradiant phase. Furthermore, the Bogoliubov excitation spectrum reveals roton-type mode softening, indicating that the phase transition also corresponds to the superfluid-to-lattice supersolid transition. Our findings provide insights into the interplay between atomic detunings and collective quantum many-body phenomena, offering potential applications in quantum simulation and optical switching technologies.

8 pages,6 figures

References in corpus (12)

• Many-Body Physics with Ultracold Gases
• Cold atoms in cavity-generated dynamical optical potentials
• Supersolid formation in a quantum gas breaking continuous translational symmetry
• Roton-type mode softening in a quantum gas with cavity-mediated long-range interactions
• Tunable-range, photon-mediated atomic interactions in multimode cavity QED
• Self-organization of a Bose-Einstein condensate in an optical cavity
• Dissipative Preparation of Spin Squeezed Atomic Ensembles in a Steady State
• Dissipation-induced instabilities of a spinor Bose-Einstein condensate inside an optical cavity
• Two-mode Dicke model from non-degenerate polarization modes
• Superradiant Phase Transition of Fermi Gases in a Cavity across a Feshbach Resonance
• Nonlinear Floquet dynamics of spinor condensates in an optical cavity: Cavity-amplified parametric resonance
• Non-equilibrium phases of Fermi gas inside a cavity with imbalanced pumping