Quantum Fluctuation-induced Phase Transition in S ¼ 1=2 XY-like Heisenberg Antiferromagnets on the Triangular Lattice
Quantum Fluctuation-induced Phase Transition in S ¼ 1=2 XY-like Heisenberg Antiferromagnets on the Triangular Lattice
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DOI：
10.1143/jpsj.73.1798
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发表时间：
2004-03
影响因子：
1.7
通讯作者：
S. Yoshikawa;K. Okunishi;Makoto Senda;S. Miyashita
中科院分区：
文献类型：
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作者：
S. Yoshikawa;K. Okunishi;Makoto Senda;S. Miyashita
本文研究了Nikuni和Shiba首先提出的三角晶格上S =1/2 XY类海森堡反铁磁体在沿难磁化轴沿着方向施加的磁场中，由于量子涨落而导致的基态在近简并态中的选择.我们发现，所选择的基态敏感地依赖于各向异性的程度和磁场的大小。这种依赖性类似于在有限温度下的相应的经典模型中，由于熵效应，出现了各种类型的场诱导相。同时还发现，在经典和量子模型中的选择态的相似性并不存在于两腿梯形晶格中，尽管该晶格局部由三角形组成，并且在经典情况下该晶格的基态与三角形晶格的基态相同.
The selection of the ground state among nearly degenerate states due to quantum fluctuations is studied for the S =1/2 XY-like Heisenberg antiferromagnets on the triangular lattice in the magnetic field applied along the hard axis, which was first pointed out by Nikuni and Shiba. We find that the selected ground state sensitively depends on the degree of the anisotropy and the magnitude of the magnetic field. This dependence is similar to that in the corresponding classical model at finite temperatures where various types of field induced phases appear due to the entropy effect. It is also found that the similarities of the selected states in the classical and quantum models are not the case in a two-leg ladder lattice, although the lattice consists of triangles locally and the ground state of this lattice in the classical case is the same as that of the triangular lattice.