Theoretical investigation of the behavior of CuSe2O5 compound in high magnetic fields

TL;DR

This paper provides a theoretical analysis of the thermodynamic behavior of CuSe2O5 in high magnetic fields, revealing quantum phase transitions, the nature of the Luttinger liquid phase, and the behavior of the Wilson ratio.

Contribution

It offers a detailed theoretical investigation of CuSe2O5's magnetic phases and thermodynamics using analytical and numerical methods, highlighting quantum critical behavior and phase crossover.

Findings

Identification of a quantum critical field in CuSe2O5.

Observation of a crossover from gapless Luttinger liquid to gapped phase.

Wilson ratio shows anomalous enhancement near the critical field.

Abstract

Based on analytical and numerical approaches, we investigate thermodynamic properties of CuSe2O5 at high magnetic fields which is a candidate for the strong intra-chain interaction in quasi one-dimensional (1D) quantum magnets. Magnetic behavior of the system can be described by the 1D spin-1/2 XXZ model in the presence of the Dzyaloshinskii-Moriya (DM) interaction. Un- der these circumstances, there is one quantum critical field in this compound. Below the quantum critical field the spin chain system is in the gapless Luttinger liquid (LL) regime, whereas above it one observes a crossover to the gapped saturation magnetic phase. Indications on the thermodynamic curves confirm the occurrence of such a phase transition. The main characteristics of the LL phase are gapless and spin-spin correlation functions decay algebraic. The effects of zero-temperature quantum phase transition are observed even at rather high temperatures in comparison with the counterpart compounds. In addition, we calculate the Wilson ratio in the model. The Wilson ratio at a fixed temperature remains almost independent of the field in the LL region. In the vicinity of the quantum critical field, the Wilson ratio increases and exhibits anomalous enhancement.