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arXiv 0710.3097cond-mat.str-el
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自旋子在XX链中的相互作用和热力学

Interaction and thermodynamics of spinons in the XX chain

Michael Karbach, Gerhard Muller, Klaus Wiele

摘要:

利用N格点上一维自旋1/2 XX模型本征态的费米子和自旋子组成之间的映射,从两个不同的角度描述了自旋相互作用:(1)对于有限的N,所有本征态的能量表示为自旋子动量和自旋的函数,而自旋子动量和自旋是一组Bethe不等式的解。后者是在XX模型的自旋表示中进行精确热力学分析的基础。(ii)对于N ->无穷大,涉及任意数目自旋轨道的自旋组态的每一位置的能量表示为表示每个轨道的动量、填充和磁化的约化变量的函数。自旋自旋在一个单一的轨道被发现耦合的方式很好地描述了一个伊辛类等效邻居的相互作用,从铁磁切换到反铁磁填充超过临界水平。与Haldane-Shastry模型的结果进行了比较。

英文摘要:

The mapping between the fermion and spinon compositions of eigenstates in the one-dimensional spin-1/2 XX model on a lattice with N sites is used to describe the spinon interaction from two different perspectives: (i) For finite N the energy of all eigenstates is expressed as a function of spinon momenta and spinon spins, which, in turn, are solutions of a set of Bethe ansatz equations. The latter are the basis of an exact thermodynamic analysis in the spinon representation of the XX model. (ii) For N -> infinity the energy per site of spinon configurations involving any number of spinon orbitals is expressed as a function of reduced variables representing momentum, filling, and magnetization of each orbital. The spins of spinons in a single orbital are found to be coupled in a manner well described by an Ising-like equivalent-neighbor interaction, switching from ferromagnetic to antiferromagnetic as the filling exceeds a critical level. Comparisons are made with results for the Haldane-Shastry model.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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