Chirality in spin-1/2 zigzag XY chain: Low-temperature density-matrix renormalization group study

TL;DR

This study investigates the temperature-dependent behavior of spin chirality in a one-dimensional spin-1/2 zigzag XY chain using low-temperature density-matrix renormalization group methods, revealing the disappearance of long-range order at finite temperatures and temperature-induced chiral correlations.

Contribution

First application of low-temperature DMRG to analyze dynamical and static chirality correlations in a zigzag XY chain at finite temperatures.

Findings

Chiral long-range order vanishes at finite temperature in the chiral phase.

Static chiral and spin correlations are enhanced with increasing temperature in the dimer phase.

Temperature-induced chiral correlations indicate chiral states in excited states.

Abstract

We study spin chirality for a spin-1/2 zigzag XY chain at low temperature by applying a low-temperature density-matrix renormalization group technique. We calculate temperature dependence of dynamical and static correlations of the chirality. In a chiral phase, chiral long-range order at zero temperature disappears at finite temperature, consistent with the fact that there is no long-range order at finite temperature in one-dimensional systems with short-range interactions. In a dimer phase next to the chiral phase, we find an enhancement of static chiral correlation as well as spin correlation with increasing temperature. The enhancement corresponds to the increase of spectral weight inside a gap in the dynamical chiral-correlation function. This temperature-induced chiral correlation is a demonstration of the presence of a chiral state in excited states.