Non-Hermitian quantum impurity systems in and out of equilibrium: Noninteracting case - Archive ouverte HAL Access content directly
Journal Articles Physical Review B Year : 2020

Non-Hermitian quantum impurity systems in and out of equilibrium: Noninteracting case

Abstract

We provide systematic analysis on a non-Hermitian PT -symmetric quantum impurity system both in and out of equilibrium, based on exact computations. In order to understand the interplay between non-Hermiticity and Kondo physics, we focus on a prototypical noninteracting impurity system, the resonant level model, with complex coupling constants. Explicitly constructing biorthogonal basis, we study its thermodynamic properties as well as the Loschmidt echo starting from the initially disconnected two free fermion chains. Remarkably, we observe the universal crossover physics in the Loschmidt echo, both in the PT broken and unbroken regimes. We also find that the ground state quantities we compute in the PT broken regime can be obtained by analytic continuation. It turns out that Kondo screening ceases to exist in the PT broken regime, which was also previously predicted in the non-hermitian Kondo model. All the analytical results are corroborated against biorthogonal free fermion numerics.
Fichier principal
Vignette du fichier
YOBiSa20.pdf (1.14 Mo) Télécharger le fichier
Origin Publisher files allowed on an open archive
Licence

Dates and versions

hal-03017010 , version 1 (12-04-2023)

Licence

Identifiers

Cite

Takato Yoshimura, Kemal Bidzhiev, Hubert Saleur. Non-Hermitian quantum impurity systems in and out of equilibrium: Noninteracting case. Physical Review B, 2020, 102 (12), pp.125124. ⟨10.1103/PhysRevB.102.125124⟩. ⟨hal-03017010⟩
37 View
56 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More