Insulator-to-metal transition in Kondo insulators under strong magnetic field

TL;DR

This paper investigates the insulator-to-metal transition in Kondo insulators under strong magnetic fields using the periodic Anderson model, revealing a first-order transition near the Kondo temperature and comparing results with experimental data.

Contribution

It provides a theoretical analysis of magnetic field-induced transitions in Kondo insulators using the exact diagonalization method in infinite dimensions, highlighting the nature of the transition.

Findings

Transition occurs at a critical field near the Kondo temperature

The transition is first order in finite systems, possibly second order in the infinite limit

Results are consistent with experimental observations on YbB$_{12}$

Abstract

Magnetization curve and changes of the single-particle excitation spectra by magnetic field are calculated for the periodic Anderson model at half-filling in infinite spatial dimension by using the exact diagonalization method. It is found that the field-induced insulator-to-metal transition occurs at a critical field $H_c$, which is of the order of the single ion Kondo temperature. The transition is of first order, but could be of second order in the infinite system size limit. These results are compared with the experiments on the Kondo insulator YbB$_{12}$.