title: Magnetization process, bipartite entanglement, and enhanced magnetocaloric effect of the exactly solved spin-1/2 Ising-Heisenberg tetrahedral chain.
abstract: The frustrated spin-1/2 Ising-Heisenberg ladder with Heisenberg intra-rung and Ising inter-rung interactions is exactly solved in a longitudinal magnetic field by taking advantage of the local conservation of the total spin on each rung and the transfer-matrix method. We have rigorously calculated the ground-state phase diagram, magnetization process, magnetocaloric effect, and basic thermodynamic quantities for the model, which can be alternatively viewed as an Ising-Heisenberg tetrahedral chain. It is demonstrated that a stepwise magnetization curve with an intermediate plateau at half of the saturation magnetization is also reflected in respective stepwise changes of the concurrence serving as a measure of bipartite entanglement. The ground-state phase diagram and zero-temperature magnetization curves of the Ising-Heisenberg tetrahedral chain are contrasted with the analogous results of the purely quantum Heisenberg tetrahedral chain, which have been obtained through density-matrix renormalization group (DMRG) calculations. While both ground-state phase diagrams fully coincide in the regime of weak inter-rung interaction, the purely quantum Heisenberg tetrahedral chain develops Luttinger spin-liquid and Haldane phases for strongly coupled rungs, which are absent in the Ising-Heisenberg counterpart model.
authors.affiliation: Department of Theoretical Physics and Astrophysics, Faculty of Science, P. J. Šafárik University, Park Angelinum 9, 040 01, Košice, Slovak Republic.
authors.forename: Jozef
authors.initials: J
authors.lastname: Strečka
authors.affiliation: Departamento de Ciencias Exatas, Universidade Federal de Lavras, 37200-000, Lavras-MG, Brazil.
authors.forename: Onofre
authors.initials: O
authors.lastname: Rojas
authors.affiliation: Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, 1 Svientsitskii Street, L'viv-11, 79011, Ukraine.
authors.forename: Taras
authors.initials: T
authors.lastname: Verkholyak
authors.affiliation: Instituto de Física, Universidade Federal de Alagoas, 57072-970, Maceio-AL, Brazil.
authors.forename: Marcelo L
authors.initials: ML
authors.lastname: Lyra
mesh_terms: D003198:Computer Simulation; D004735:Energy Transfer; D006358:Hot Temperature; D060526:Magnetic Fields; D008956:Models, Chemical; D011789:Quantum Theory; D013113:Spin Labels
chemical_list: D013113:Spin Labels