Spin polarons in triangular antiferromagnets

TL;DR

This paper investigates the behavior of a single hole in a 2D triangular antiferromagnet using the t-J model, revealing how quasiparticle features depend on the ratio J/t and comparing with other computational methods.

Contribution

It introduces a string-based description of one-hole states in triangular antiferromagnets and calculates the spectral function using a projection technique, highlighting the dependence on J/t ratio.

Findings

Low-lying quasiparticle bands for large J/t separated by a gap.

Spectrum broadens and the gap vanishes for small J/t.

Comparison with SCBA and numerical data confirms results.

Abstract

The motion of a single hole in a 2D triangular antiferromagnet is investigated using the t-J model. The one-hole states are described by strings of spin deviations around the hole. Using projection technique the one-hole spectral function is calculated. For large J/t we find low-lying quasiparticle-like bands which are well separated from an incoherent background by a gap of order J. However, for small J/t this gap vanishes and the spectrum becomes broad over an energy range of several t. The results are compared with SCBA calculations and numerical data.