Temperature dependent band structure of the Kondo insulator

TL;DR

This study uses quantum Monte Carlo simulations to explore how the band structure of a Kondo insulator changes with temperature, revealing a complex low-temperature structure and a temperature-driven metal-insulator transition.

Contribution

It provides the first detailed temperature-dependent analysis of the Kondo insulator's band structure using sign-free QMC simulations at very low temperatures.

Findings

Identification of two characteristic temperatures: Kondo and coherence temperatures.

Observation of a temperature-induced metal-insulator transition.

Discovery of intricate low-temperature band structure features.

Abstract

We present a Qantum Monte Carlo (QMC) study of the temperature dependent dynamics of the Kondo insulator. Working at the so-called symmetrical point allows to perform minus-sign free QMC simulations and thus reach temperatures of less than 1% of the conduction electron bandwidth. Study of the temperature dependence of the single particle Green's function and dynamical spin correlation function shows a surprisingly intricate low temperature band structure and gives evidence for two characteristic temperatures, which we identify with the Kondo and coherence temperature, respectively. In particular, the data show a temperature induced metal-insulator transition at the coherence temperature.