Realization of a non-Hermitian optical Raman lattice for ultracold fermions*

The recent advances in non-Hermitian physics open new possibilities for exploring unprecedented quantum states in an open atomic system. In our previous study[1], we have realized non-Hermitian spin-orbit coupled bands for ultracold fermions in bulk, and demonstrated the topological nature of non-Hermitian energy band near the band closing point when the Parity-Time symmetry breaking transition occurs. In this talk, we report our progress on the experimental development of the non-Hermitian optical Raman lattice, which generalizes non-Hermitian spin-orbit coupling into the lattice system. Focusing on the time evolution of spin texture in Bloch bands, we explore the distinct features induced by a highly controllable spin-dependent dissipation and spin-orbit coupling. It is expected that this non-Hermitian platform would allow us to further expand the possibilities of studying the non-Hermitian topological phases in lattices.