Correlation-induced sensitivity and non-Hermitian skin effect of quasiparticles

Non-Hermitian (NH) Hamiltonians have been shown to exhibit unique signatures, including the NH skin effect and an exponential spectral sensitivity with respect to boundary conditions. Here, we investigate as to what extent these remarkable phenomena, recently predicted and observed in a broad range...

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Bibliographic Details
Main Authors: Tommaso Micallo, Carl Lehmann, Jan Carl Budich
Format: Article
Language:English
Published: American Physical Society 2023-11-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.5.043105
Description
Summary:Non-Hermitian (NH) Hamiltonians have been shown to exhibit unique signatures, including the NH skin effect and an exponential spectral sensitivity with respect to boundary conditions. Here, we investigate as to what extent these remarkable phenomena, recently predicted and observed in a broad range of settings, may also occur in closed correlated fermionic systems that are governed by a Hermitian many-body Hamiltonian. There, an effectively NH quasiparticle description naturally arises in the Green's function formalism due to interparticle scattering that represents an inherent source of dissipation. As a concrete platform we construct an extended interacting Su-Schrieffer-Heeger (SSH) model subject to varying boundary conditions, which we analyze using exact diagonalization and nonequilibrium Green's function methods. That way, we clearly identify the presence of the aforementioned NH phenomena in the quasiparticle properties of this Hermitian model system.
ISSN:2643-1564