Local environment effects on a charge carrier injected into an Ising chain

TL;DR

This paper provides numerically exact spectral functions for a charge carrier in an Ising chain at finite temperature, revealing resonance structures due to magnetic domain trapping, with implications for disordered alloy models.

Contribution

It presents the first numerically exact spectral functions for a charge carrier in an Ising chain, including a detailed analysis of resonance structures and an analytic approximation.

Findings

Spectral functions show resonance structures from magnetic domain trapping.

Results connect to disordered binary alloy models.

Provides an accurate analytic approximation for spectral functions.

Abstract

We present numerically exact results for the spectral function of a single charge carrier that is injected into an Ising chain at finite temperature $T$. Both ferromagnetic and antiferromagnetic coupling between the Ising spins are considered. The interaction between the carrier and the Ising spins is assumed to be on-site and of Ising type, as well. We find that the carrier's spectral function exhibits a distinctive fine structure of resonances that are due to the temporary entrapping of the carrier inside small magnetic domains. The connection to models of disordered binary alloys where similar effects can occur is explained. We use these results to construct an accurate (quasi)analytic approximation for low and medium-$T$ spectral functions.