Multicritical behavior of two-dimensional anisotropic antiferromagnets in a magnetic field
Multicritical behavior of two-dimensional anisotropic antiferromagnets in a magnetic field
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二维各向异性反铁磁体在磁场中的多临界行为
DOI：
10.1103/physrevb.76.024436
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发表时间：
2007
影响因子：
3.7
通讯作者：
E. Vicari
中科院分区：
文献类型：
--
作者：
A. Pelissetto;E. Vicari
本文研究了各向异性的相图和多临界行为，
正方晶格上的海森堡反铁磁体
场沿着易磁化轴。我们认为，除了伊辛和XY临界
线，该相图呈现了一阶自旋触发器线，
T=0，如在三维情况下。通过使用场论，我们表明，
这些过渡线相交的多临界点不可能是O（3）对称的
并且发生在有限的温度下。我们还预测了临界温度
的转变线的变化与磁场和单轴
在弱各向异性极限下的各向异性。
We study the phase diagram and multicritical behavior of anisotropic
Heisenberg antiferromagnets on a square lattice in the presence of a magnetic
field along the easy axis. We argue that, beside the Ising and XY critical
lines, the phase diagram presents a first-order spin-flop line starting from
T=0, as in the three-dimensional case. By using field theory we show that the
multicritical point where these transition lines meet cannot be O(3) symmetric
and occurs at finite temperature. We also predict how the critical temperature
of the transition lines varies with the magnetic field and the uniaxial
anisotropy in the limit of weak anisotropy.