Non-Hermitian tight-binding Hamiltonians usually describe open systems with gain or loss. These toy models are known to exhibit interesting signatures such as skin effects. This paper (arXiv.2302.00019) proposes a new microscopic explanation of the origin of non-Hermitian-ness. Despite the whole system’s Hamiltonian being Hermitian, the effective Hamiltonian for the quasiparticles can be non-Hermitian due to dissipations from particle-particle interactions. This effective Hamiltonian for the quasiparticles shows the same non-Hermitian signatures as in previous studies. This journal club will be in three parts: a brief review of the non-Hermitian tight-binding system, a short derivation of effective Hamiltonian description in Green function formalism, and the model and results presented in the paper.
