Thermodynamics of a spin-1/2 XYZ Heisenberg chain with a Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates the thermodynamic properties of a spin-1/2 XYZ Heisenberg chain with Dzyaloshinskii-Moriya interaction, revealing phase transitions and phase diagrams relevant for experimental detection.

Contribution

It provides a detailed numerical analysis of thermodynamics in this model, including an exactly solvable limit, and maps out phase transitions based on entropy and specific heat data.

Findings

Quantum phase transition between magnetic phases at finite θ for U'/U>1

Transition between ferromagnetic and paramagnetic phases at θ=0 for U'/U<1

Refined ground-state phase diagram derived from low-temperature behavior

Abstract

We study the thermodynamics of an XYZ Heisenberg chain with Dzyaloshinskii-Moriya interaction, which describes the low-energy behaviors of a one-dimensional spin-orbit-coupled bosonic model in the deep insulating region. The entropy and the specific heat are calculated numerically by the quasi-exact transfer-matrix renormalization group. In particular, in the limit $U^\prime/U\rightarrow\infty$, our model is exactly solvable and thus serves as a benchmark for our numerical method. From our data, we find that for $U^\prime/U>1$ a quantum phase transition between an (anti)ferromagnetic phase and a Tomonaga-Luttinger liquid phase occurs at a finite $\theta$, while for $U^\prime/U<1$ a transition between a ferromagnetic phase and a paramagnetic phase happens at $\theta=0$. A refined ground-state phase diagram is then deduced from their low-temperature behaviors. Our findings provide an alternative way to detect those distinguishable phases experimentally.