Field-induced phase transition in the periodic Anderson model

TL;DR

This study explores how magnetic fields induce a phase transition in a Kondo insulator modeled by the periodic Anderson model, revealing a transition to a transverse antiferromagnetic insulator at low temperatures.

Contribution

It demonstrates, through dynamical mean field theory and quantum Monte Carlo simulations, that magnetic fields cause a phase transition from a Kondo insulator to an antiferromagnetic insulator, highlighting the suppression of Kondo singlets.

Findings

Magnetic field induces a transverse antiferromagnetic insulator phase.

Divergence of staggered spin susceptibility signals antiferromagnetic instability.

Magnetic field suppresses Kondo singlet formation.

Abstract

We investigate the effect of magnetic fields on a Kondo insulator by using the periodic Anderson model. The analysis by dynamical mean field theory combined with quantum Monte Carlo simulations reveals that the magnetic field drives the Kondo insulator to a transverse antiferromagnetic insulator at low temperatures. We calculate the staggered spin susceptibility and find its divergence signaling the antiferromagnetic instability. Further investigation of the spin correlation functions and the magnetization process clarifies how the magnetic field suppresses the Kondo singlet formation and induces the transverse antiferromagnetic ordering.