Spin vortices, skyrmions and Kosterlitz-Thouless transition in the two-dimensional antiferromagnet
Spin vortices, skyrmions and Kosterlitz-Thouless transition in the two-dimensional antiferromagnet
复制标题
二维反铁磁体中的自旋涡流、斯格明子和 Kosterlitz-Thouless 转变
DOI：
10.1088/1742-6596/428/1/012040
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
T. Yanagisawa
中科院分区：
文献类型：
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作者：
I. Hase;T. Yanagisawa;S.-Z. Lin and X. Hu;T. Yanagisawa
本文在非线性sigma模型的基础上研究了二维反铁磁体中的自旋涡旋激发。将二维海森堡量子反铁磁体模型映射到（2+ 1）维非线性σ模型上。2D非线性西格玛模型有一个瞬子（或skyrmion）的解决方案，它描述了自旋涡旋型的激发。将瞬子的量子涨落归结为对库仑气体的研究，二维非线性σ模型的瞬子气体处于等离子体相中。我们将这幅瞬子气体的图像推广到（2+ 1）D非线性sigma模型。我们表明，使用一些近似，有一个Kosterlitz无过渡从等离子体相的分子相的温度降低。
We investigate spin-vortex excitations in the two-dimensional antiferromagnet on the basis of the nonlinear sigma model. The model of two-dimensional Heisenberg quantum antiferromagnet is mapped onto the (2+ 1) D nonlinear sigma model. The 2D nonlinear sigma model has an instanton (or skyrmion) solution which describes an excitation of spin-vortex type. Quantum fluctuations of instantons are reduced to the study of the Coulomb gas, and the gas of instantons of the 2D nonlinear sigma model is in the plasma phase. We generalize this picture of instanton gas to the (2+ 1) D nonlinear sigma model. We show, using some approximation, that there is a Kosterlitz-Thouless transition from the plasma phase to the molecular phase as the temperature is lowered.