# Antiferromagnetic phase of the Kondo-insulator

## TL;DR

This paper analyzes the antiferromagnetic phase of the Kondo insulator using bond fermion techniques, showing good agreement with numerical methods and discussing the phase's electronic properties and potential experimental implications.

## Contribution

It introduces a bond fermion approach to study the band structure of the antiferromagnetic Kondo insulator, aligning well with dynamical cluster approximation results.

## Key findings

- Band structure changes with J/t are qualitatively reproduced.
- A semimetallic phase exists at small exchange constants.
- Good agreement with numerical spectral functions is achieved.

## Abstract

We discuss the quasiparticle band structure of the antiferromagnetic phase of the planar Kondo lattice model with a half-filled conduction band, the so-called Kondo insulator. The band structure is obtained by bond fermion technique and good agreement is obtained with the single particle spectral function obtained by Dynamical Cluster Approximation. In particular, various changes of the band structure with J/t observed in the numerical spectra are reproduced qualitatively by the calculation. In the absence of Fermi surface nesting we find a semimetallic phase for sufficiently small exchange constant and possible experimental consequences are discussed