Anomaly in the phase diagram of the spin quantum 1/2 anisotropic Heisenberg antiferromagnet model with Dzyaloshinskii-Moriya interaction: A low temperature analysis

摘要

We will study phase diagram the quantum spin-1/2 anisotropic Heisenberg antilerromagnet model in the presence or a Dzyaloshinskii-Moriya interaction (D) and a unilorm longitudinal (H) magnetic field, where we have observed an anomaly at low temperatures. Using the effective-00d theory with a finite cluster N=2 spin (EFT-2) we calculate the phase diagram in the H-D plane on a simple cubic lattice (z=6). We analyzed the cases: anisotropic Heisenberg - case I: (Delta = 1), anisotropic Heisenberg - case II: (Delta = 0.5) and anisotropic Heisenberg - case III. (Delta = 0), where only second order phase transitions are observed. (C) 2015 Elsevier B.V. All rights reserved.