Dissipative two-dimensional Raman lattice

We show that a dissipative two-dimensional Raman lattice can be engineered in a two-component ultracold atomic gas, where the interplay of the two-dimensional spin-orbit coupling and light-induced atom loss gives rise to a density flow diagonal to the underlying square lattice. The flow is driven by the non-Hermitian corner skin effect, under which eigenstates localize toward one corner of the system. We illustrate that the topological edge states of the system can only be accounted for by the non-Bloch band theory where the deformation of the bulk eigenstates are explicitly considered. The directional flow can be detected through the dynamic evolution of an initially localized condensate in the lattice, or by introducing an immobile impurity species that interact spin selectively with a condensate in the ground state of the Raman lattice.