Thermal first-order phase transitions, Ising critical points, and reentrance in the Ising-Heisenberg model on the diamond-decorated square lattice in a magnetic field
| Autor: | Strecka, Jozef, Karlova, Katarina, Verkholyak, Taras, Caci, Nils, Wessel, Stefan, Honecker, Andreas |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 107, 134402 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.107.134402 |
| Popis: | The thermal phase transitions of a spin-1/2 Ising-Heisenberg model on the diamond-decorated square lattice in a magnetic field are investigated using a decoration-iteration transformation and classical Monte Carlo simulations. A generalized decoration-iteration transformation maps this model exactly onto an effective classical Ising model on the square lattice with temperature-dependent effective nearest-neighbor interactions and magnetic field strength. The effective field vanishes along a ground-state phase boundary of the original model, separating a ferrimagnetic and a quantum monomer-dimer phase. At finite temperatures this phase boundary gives rise to an exactly solvable surface of discontinuous (first-order) phase transitions, which terminates in a line of Ising critical points. The existence of discontinuous reentrant phase transitions within a narrow parameter regime is reported and explained in terms of the low-energy excitations from both phases. These exact results, obtained from the mapping to the zero-field effective Ising model are corroborated by classical Monte Carlo simulations of the effective model. Comment: 17 pages, 15 figures |
| Databáze: | arXiv |
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