Topological Entanglement Across Quantum Phase Transition in Spin-Orbit coupled Bose-Einstein Condensate
Kashif Ammar Yasir, Wu-Ming Liu, Xianlong Gao
Abstract Spin–orbit–coupled Bose–Einstein condensates are a central platform for exploring quantum phase transitions and synthetic quantum matter, yet how entanglement behaves across these transitions remains largely unexplored. We analyze bipartite entanglement between synthetically dressed pseudo–spin states in a cavity–QED environment using a quantum–Langevin approach, where the coupled atom–photon fluctuations are governed by a non-Hermitian drift matrix. Steady-state quantum correlations are quantified through logarithmic negativity and entanglement fidelity. When cavity loss dominates over atomic dissipation, the cavity mediates only dispersive coupling between the pseudo-spins, and the entanglement remains weak and broadly distributed across the transition from the stripe-like mixed state to the plane-wave state. When atomic dissipation becomes the dominant channel, the fluctuation spectrum undergoes a qualitative and topological change: a set of spin-localized, edge-like photonic modes emerges. These non-Hermitian topological edge modes act as spectrally selective pathways that confine cavity-generated fluctuations around the pseudo–spin manifold, enhance their phase-space overlap, and produce sharply bounded regions of strong spin–spin entanglement in the Raman parameter plane. Entanglement fidelity verifies that the enhancement originates from topological edge-mode localization rather than from dissipation itself. Thus, non-Hermitian topological edge physics reorganizes the entanglement landscape across the phase transition of synthetically dressed atomic states, revealing a pathway to edge-mode-enhanced quantum entanglement in hybrid quantum systems.
•Jun 8, 2026•0 citations