Emergent Fermi surface in a many-body non-Hermitian fermionic chain

Abstract

Fermion accumulation due to asymmetric pumping in a one-dimensional chain is found not only to resemble a Fermi surface in real space, but also to behave like a genuine Fermi surface in its entropy scaling behavior. Nearest-neighbor repulsion is also found to induce competing charge density waves that may erode the real-space Fermi surface. The underlying physics surrounding criticality and localization is further analyzed with complex spectral flows, highlighting the interplay between quantum degenerate pressure, non-Hermitian pumping, and many-body effects.