Dissipative Kondo physics in the Anderson Impurity Model with two-body losses

TL;DR

This paper investigates how two-body dissipative processes affect Kondo physics in the Anderson Impurity Model, revealing that strong correlations can protect and re-emerge Kondo signatures despite dissipation.

Contribution

It introduces a dissipative Anderson model with two-body losses and demonstrates how Kondo physics persists and is modified under correlated dissipation using NCA and numerical simulations.

Findings

Kondo signatures are robust under two-body dissipation

Spectral function shows destruction and re-emergence of the Kondo peak

Strong correlations suppress impurity-bath losses

Abstract

We study a dissipative version of the Anderson Impurity model, where an interacting impurity is coupled to a fermionic reservoir and exposed to Markovian dissipation in the form of two-body losses. Using a self-consistent hybridization expansion based on the Non-Crossing Approximation (NCA) we compute the dynamics of the impurity, its steady-state and spectral function. We show that the interplay between strong Coulomb repulsion and correlated dissipation gives rise to robust signatures of Kondo physics both at weak and strong losses. These include a strongly suppressed spin relaxation rate, displaying a characteristic Kondo-Zeno crossover and a spectral function where doublon band is quickly destroyed by dissipation while the coherent Kondo peak remains visible for weak losses, then disappears at intermediate values and finally re-emerge as the system enters in the Kondo-Zeno regime. As compared to the case of single particle losses we show that two-body dissipation protects Kondo physics. The picture obtained with NCA is confirmed by numerical simulations of exact dynamics on finite-size chains. We interpret these results using a dissipative Schrieffer-Wolff transformation, which leads to an effective Kondo model with residual impurity-bath losses which are suppressed by strong correlations or strong losses.