Critical Kondo destruction in a pseudogap Anderson model: scaling and relaxational dynamics

TL;DR

This paper investigates the critical destruction of Kondo screening in a pseudogap Anderson model, revealing finite-temperature scaling functions and linear relaxation rates, with implications for heavy fermion quantum criticality.

Contribution

It provides the first detailed analysis of finite-temperature scaling and relaxational dynamics at the quantum critical point of the pseudogap Anderson model using quantum Monte Carlo and large-N methods.

Findings

Finite-temperature scaling functions are obtained near the quantum critical point.

Relaxation rates for spin and single-particle excitations are linear in temperature.

Results have implications for understanding quantum criticality in heavy fermion metals.

Abstract

We study the pseudogap Anderson model as a prototype system for critical Kondo destruction. We obtain finite-temperature (T) scaling functions near its quantum critical point, using a continuous-time quantum Monte Carlo method and also considering a dynamical large-N limit. We are able to determine the behavior of the scaling functions in the typically-difficult-to-access quantum-relaxational regime (hbar w < k_B T), and conclude that the relaxation rates for both the spin and single-particle excitations are linear in temperature. We discuss the implications of these results for the quantum critical phenomena in heavy fermion metals.