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

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 $U^{\prime }/U\to \infty$, 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 $\hat{I}¸$, while for $U^{\prime }/U<1$ a transition between a ferromagnetic phase and a paramagnetic phase happens at $\hat{I}¸=0$. 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.

accepted by Phys. Rev. B, title changed