Spin frustration of a spin-1/2 Ising-Heisenberg three-leg tube as an indispensable ground for thermal entanglement

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:409

Article

Strecka, Jozef¹  Alecio, Raphael Cavalcante²  Lyra, Marcelo L.²  Rojas, Onofre³ 

[1] Safarik Univ, Dept Theoret Phys & Astrophys, Fac Sci, Pk Angelinum 9, Kosice 04001, Slovakia

[2] Univ Fed Alagoas, Inst Fis, BR-57072970 Maceio, AL, Brazil

[3] Univ Fed Lavras, Dept Fis, BR-37200000 Lavras, MG, Brazil

关键词: Ising-Heisenberg tube;    Spin frustration;    Thermal entanglement;    Chirality;   

DOI  :  10.1016/j.jmmm.2016.02.095

来源: Elsevier

【 摘 要 】

The spin-1/2 Ising-Heisenberg three-leg tube composed of the Heisenberg spin triangles mutually coupled through the Ising inter-triangle interaction is exactly solved in a zero magnetic field. By making use of the local conservation for the total spin on each Heisenberg spin triangle the model can be rigorously mapped onto a classical composite spin-chain model, which is subsequently exactly treated through the transfer-matrix method. The ground-state phase diagram, correlation functions, concurrence, Bell function, entropy and specific heat are examined in detail. It is shown that the spin frustration represents an indispensable ground for a thermal entanglement, which is quantified by the quantum concurrence. The specific heat displays diverse temperature dependences, which may include a sharp low-temperature peak mimicking a temperature-driven first-order phase transition. It is convincingly evidenced that this anomalous peak originates from massive thermal excitations from the doubly degenerate ground state towards an excited state with a high macroscopic degeneracy due to chiral degrees of freedom of the Heisenberg spin triangles. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free