Spin-1 J1 - J2 - J3 ferromagnetic Heisenberg model with an easy-plane crystal field on the cubic lattice: A bosonic approach

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:407

Article

Carvalho, D. C.^1,2  Pires, A. S. T.²  Mol, L. A. S.² 

[1] Inst Fed Norte Minas Gerais, Fazenda Varginha, Km 02 Rodovia Salinas Taiobeiras, BR-39560000 Salinas, MG, Brazil

[2] Univ Fed Minas Gerais, Dept Fis, Inst Ciencies Exatas, CP 702, BR-30123970 Belo Horizonte, MG, Brazil

关键词: Quantum phase transition;    Bond-operator formalism;    Quantum spin liquid;    Frustrated Heisenberg model;    Single-ion anisotropy;   

DOI  :  10.1016/j.jmmm.2016.02.001

来源: Elsevier

【 摘 要 】

We examine the phase diagram of the spin-1 J(1)- J(2)- J(3) ferromagnetic Heisenberg model with an easy plane crystal field on the cubic lattice, in which J(1) is the ferromagnetic exchange interaction between nearest neighbors, J(2) is the antiferromagnetic exchange interaction between next-nearest neighbors and J(3) is the antiferromagnetic exchange interaction between next-next-nearest neighbors. Using the bond operator formalism, we investigate the phase transitions between the disordered paramagnetic phase and the ordered ones. We show that the nature of the quantum phase transitions changes as the frustration parameters (are varied. The zero-temperature phase diagram exhibits second- and first order transitions, depbnding on the energy gap behavior. Remarkably, we find a disordered nonmagnetic phase, even in the absence of a crystal field, which is suggested to be a quantum spin liquid candidate. We also depict the phase diagram at finite temperature for some values of crystal field and frustration parameters. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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