Emergent spin phenomena in non-hermitian Rashba-Hubbard model

Non-hermitian Hamiltonians have recently become important not just in photonics but also in condensed matter systems. In this context, we introduce a general model for a non-hermitian tight-binding Hamiltonian with Rashba spin-orbit coupling. In the presence of a Hubbard repulsion term, we explore the low-energy effective spin exchange and Dzyloshinskii-Moriya interaction in this model. Depending on the choice of the lattice, we find that spin non-collinearity and frustration are modified. Finally, we discuss the possible material realization of the model.