Two-dimensional Su-Schrieffer-Heeger model with imaginary potentials and nonreciprocal couplings

We examine the 2D-SSH model and focus on its topological states and skin effects resulting from imaginary potentials and nonreciprocal couplings. Our calculations demonstrate that inducing topological edge and corner states allows for different topological phase transitions in the 2D-SSH model. The topological phase transition is achieved by adjusting the ratio of the intercell electron hopping to the intracell electron hopping. The PT symmetry of the system is destroyed when an imaginary potential is present. If non-reciprocal effects are introduced, then skin effects will be seen. This work contributes to understanding how the interplay between imaginary potentials and nonreciprocal couplings modulates the skin effects and topological states in 2D-SSH model.