2026/03/03 by Hannah Kleine-Pollmann, Ludwig Mathey · 1 voice
Physics and Astronomy · #cond-mat.quant-gas
We propose to combine Bose-Einstein condensation in higher Bloch bands and a driven-dissipative cavity-BEC system into a hybrid light-matter platform. Specifically, the condensate is trapped in a bipartite s-px-py-lattice, with a tunable energy offset. This enables a controlled population transfer from the s-orbital to the nearly degenerate px and py orbitals. The system forms a chiral ground state with px ± i py symmetry, with staggered orbital currents. By increasing the transverse pump strength, we drive the system into the superradiant phase, resulting in a self-organized, density checkerboard, which rectifies the staggered chiral order into a topological superfluid state. Using truncated Wigner simulations and complementary mean-field analysis, we determine the phase transition into this state as first order. Our results show that higher-band condensates coupled to a cavity provide a promising platform for engineering non-trivial orbital order and topological superfluid phases in quantum optical many-body systems.