Single-ion anisotropy effects on the demagnetization process of the alternating weak-rung interacting mixed spin-(1/2, 1) Ising-Heisenberg double saw-tooth ladders

Abstract

The entropy and cooling property of the mixed spin-(1/2, 1) Ising-Heisenberg double saw-tooth ladder are rigorously examined under an adiabatic demagnetization process using the classical transfer-matrix formalism. The model is characterized once by XXX and once by XX interactions between the interstitial Heisenberg dimers. An Ising-type coupling links spins localized on the legs and rungs. We investigate the ability of cooling/heating of the models nearby some typical critical points. It is evidenced that both models exhibit an enhanced magnetocaloric effect in a proximity of the magnetization steps and jumps. During an adiabatic demagnetization process, a sharp temperature drop is seen close to the first-order zero-temperature phase transitions. We conclude that the single-ion anisotropy considered for the integer spins plays an essential role to determine an efficiency of the magnetocaloric effect of the models under consideration.

Магнетокалоричний ефект у спін-1/2 одновимірній XX моделі з двома регулярнозмінними g-факторами

“…In view of the problem under consideration, it is also pertinent to mention that there are a number of papers, where the magnetocaloric effect in spin systems (both one- [22,27,45,46,[57][58][59][60][61][62], and twodimensional ones [63][64][65]) was studied on the basis of rigorous results obtained in the framework of various approaches. In particular, the MCE in the spin- 1 2 𝑋𝑋 1D model with three-spin interactions of the types 𝑋𝑍𝑋 + 𝑌 𝑍𝑌 and 𝑋𝑍𝑌 − 𝑌 𝑍𝑋 was considered in work [22] using the one-dimensional Jordan-Wigner transformation.…”

“…In papers [45] and [27], the isentropes for the spin-( 12 , 𝑠) Ising-Heisenberg rhombic chain were analyzed using the decoration-iterative transformation, and those for the spin- 1 2 𝑋𝑋 magnetoelectric chain with zigzag geometry were studied in the framework of the fermionization method. In work [46], by applying the transfer matrix technique to the spin-1 2 𝑋𝑋𝑍 one-dimensional model, and, in work [62] for the spin-( 12 , 1) decorated Ising-Heisenberg sawtooth ladder, the Grüneisen magnetic parameters, besides the isentropes, were also calculated to describe the MCE.…”

Tomonaga–Luttinger Spin Liquid and Kosterlitz–Thouless Transition in the Spin-1/2 Branched Chains: The Study of Topological Phase Transition

“…The magnetization of 1-D Heisenberg chain models reveals fascinating features such as an intermediate plateau [17,18,[26][27][28][29][30][31][32][33][34][35][36], jumps and steps [37][38][39][40], and spin liquid states [24,25,41,42]. In recent works, the ground-state phase diagram and the low-temperature magnetization process of several spin-1/2 Heisenberg branched chains have been examined, whose magnetic structure is inspired by the heterobimetallic coordination polymers [43,44].…”