Non-Hermitian Topological Theory of Finite-Lifetime Quasiparticles: Prediction of Bulk Fermi Arc Due to Exceptional Point

Abstract

We introduce a topological theory to study quasiparticles in interacting and/or disordered many-body systems, which have a finite lifetime due to inelastic and/or elastic scattering. The one-body quasiparticle Hamiltonian includes both the Bloch Hamiltonian of band theory and the self-energy due to interactions, which is non-Hermitian when quasiparticle lifetime is finite. We study the topology of non-Hermitian quasiparticle Hamiltonians in momentum space, whose energy spectrum is complex. The interplay of band structure and quasiparticle lifetime is found to have remarkable consequences in zero- and small-gap systems. In particular, we predict the existence of topological exceptional point and bulk Fermi arc in Dirac materials with two distinct quasiparticle lifetimes.

5 pages, 3 figures

Cited by in corpus (11)

• Topological Origin of Non-Hermitian Skin Effects
• Periodic Table for Topological Bands with Non-Hermitian Bernard-LeClair Symmetries
• Fate of fractional quantum Hall states in open quantum systems: characterization of correlated topological states for the full Liouvillian
• Disorder-induced exceptional points and nodal lines in Dirac superconductors
• Disorder-driven Phase Transitions of Second-order Non-Hermitian Skin Effects
• R-DMFT study of a non-Hermitian skin effect for correlated systems: analysis based on a pseudo-spectrum
• Fourth-Order Exceptional Points in Correlated Quantum Many-Body Systems
• Evolution of spectral topology in one-dimensional long-range nonreciprocal lattices
• Machine learning of mirror skin effects in the presence of disorder
• Supermetal-insulator transition in a non-Hermitian network model
• Non-Hermitian topology in molecules: Prediction of fractional quantum number