Mixed-spin system with supersolid phases: Magnetocaloric effect and thermal properties

TL;DR

This study explores the thermal and magnetocaloric properties of frustrated mixed-spin systems with supersolid phases, revealing thermal phase emergence, entropy behavior, and significant cooling effects near critical points.

Contribution

It provides new insights into thermal fluctuations, phase transitions, and magnetocaloric effects in mixed-spin systems with supersolid phases using cluster mean field theory.

Findings

Thermal solids and insulators emerge around ground state phases.

Large cooling rates occur near critical points at low temperatures.

Sign change of magnetocaloric parameter indicates ordered phase characteristics.

Abstract

Recently, it has been shown that two dimensional frustrated mixed-spin systems with anisotropic exchange interactions display supersolid phases in their ground state phase diagrams even in the absence of long-range interactions. In this paper, using cluster mean field theory, we investigate the effects of thermal fluctuations on the ground state phases of this kind of systems and show that various thermal solids and thermal insulators emerge around the ground state solid and Mott insulating phases. We also study the thermodynamic properties and magnetocaloric effect of these systems and demonstrate that at low temperatures, a large cooling rate is seen in the vicinity of the solid-supersolid, solid-superfluid and Mott insulator-superfluid critical points, with the large accumulation of the entropy and the minimums of the isentropes. Our results show the sign change of the magnetocaloric parameter inside the solids and the Mott insulator, which is a characteristic of ordered phases.