Magnetic polarons in two-component hard core bosons

TL;DR

This paper investigates how a single hole influences spin correlations in a two-dimensional hard-core two-component Bose gas, revealing ferromagnetic order development at certain temperatures.

Contribution

It introduces a high-temperature expansion approach to analyze spin polarization around a hole in this specific quantum system, highlighting ferromagnetic tendencies.

Findings

Spins around the hole develop ferromagnetic order.

Nonzero polarization is measurable at temperatures near the hopping energy.

Fixing overall magnetization affects finite-sized system behavior.

Abstract

We use a high-temperature expansion to explore spin correlations around a single hole in a two- dimensional lattice filled with a hard-core two component bose gas. We find that the spins around the hole develop ferromagnetic order and quantify the degree of polarization at temperatures of order the hopping energy, finding a measurably nonzero polarization. We also discuss the effect of fixing the overall magnetization of the system for finite-sized systems.