Resonant level model coupled to a Sachdev-Ye-Kitaev bath

TL;DR

This paper studies the non-equilibrium behavior of a resonant level coupled to an SYK model bath, revealing temperature-dependent oscillations due to the bath's non-quasiparticle nature, with exact analytical results.

Contribution

It provides an exact analytical analysis of a resonant level coupled to an SYK bath, highlighting differences from traditional Fermi gas baths.

Findings

Temperature-dependent oscillatory decay observed

Absence of quasiparticles affects impurity dynamics

Analytical mapping to structured Fermi gas bath

Abstract

We investigate the non-equilibrium dynamics of a resonant level model coupled to a strongly interacting electron bath modeled by a Sachdev-Ye-Kitaev (SYK) model. Different from the well-investigated case of a structureless non-interacting Fermi gas bath leading to a temperature-independent exponential decay of the impurity orbital occupation, we find a temperature-dependent oscillatory decay. We attribute this difference to the lack of quasiparticles in the SYK model, which is reflected in its singular density of states at the Fermi level. Our results are exact and can be obtained analytically by mapping to a suitably structured Fermi gas bath as an ancillary model for the SYK bath.