Enhanced magnetocaloric effect in a mixed spin-(1/2, 1) Ising-Heisenberg two-leg ladder with strong-rung interaction

TL;DR

This paper exactly analyzes the magnetocaloric properties of a mixed spin-(1/2,1) Ising-Heisenberg two-leg ladder, revealing enhanced cooling/heating effects near critical points influenced by magnetic field and four-spin interactions.

Contribution

It provides an exact study of the magnetocaloric effect in a mixed spin ladder model, highlighting the role of cyclic four-spin interactions in enhancing the effect.

Findings

Magnetization exhibits plateaux and jumps at rational fractions of saturation.

Enhanced magnetocaloric effect occurs near ground-state phase transitions.

Four-spin Ising interactions significantly influence cooling/heating efficiency.

Abstract

The magnetic and magnetocaloric properties of the mixed spin-(1/2,1) Ising-Heisenberg model on a two-leg ladder with dimer-rung alternation are exactly examined under an adiabatic demagnetization process using the transfer-matrix formalism. We notify that the magnetization curve of the model exhibits plateaux as a function of the applied magnetic field and cyclic four-spin Ising interaction at certain rational fractions of the saturation value. We precisely investigate the ability of cooling/heating of the model nearby the critical points at which discontinuous ground-state phase transition occurs. It is evidenced that the model manifests an enhanced magnetocaloric effect in a proximity of the magnetization steps and jumps, accompanying with the plateaux and jumps of correlation function of the dimer spins. We conclude that not only the cooling/heating capability of the model could be pleasantly demonstrated by the applied magnetic field variations, but also a typical cyclic four-spin Ising interaction plays essential role to determine an efficiency of the magnetocaloric effect of the model.