On the Finite Temperature Drude Weight of the Anisotropic Heisenberg Chain
On the Finite Temperature Drude Weight of the Anisotropic Heisenberg Chain
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DOI：
10.1143/jpsjs.74s.181
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发表时间：
2005-02
影响因子：
1.7
通讯作者：
J. Benz;T. Fukui;A. Klümper;C. Scheeren
中科院分区：
文献类型：
--
作者：
J. Benz;T. Fukui;A. Klümper;C. Scheeren
本文研究了自旋为1/2XXZ的链在无带隙区的Drude重量D（T）。热力学贝特分析（TBA）以两种不同的方式应用。在第一个应用中，我们采用了磁振子及其束缚态的粒子基。在这种情况下，我们重新推导并大大扩展了文献中的早期工作。然而，在我们的调查过程中，我们发现了一些论点，这些论点对TBA在这种情况下的适用性表示怀疑。在第二个应用中，通过使用自旋和反自旋粒子基础，我们得到完全不同的结果。只有当各向异性参数Δ接近于0时，我们才发现D（T）是温度的单调衰减函数。当Δ接近1时，行为完全不同，显示出有限的温度最大值。同样对于各向同性反铁磁链（Δ=1），D（T）的结果对于T =0是有限的，对于T >0也是有限的，在T =0处具有无穷大的正斜率。
We present a study of the Drude weight D ( T ) of the spin-1/2 X X Z chain in the gapless regime. The thermodynamic Bethe ansatz (TBA) is applied in two different ways. In the first application we employ the particle basis of magnons and their bound states. In this case we rederive and considerably extend earlier work in the literature. However, in the course of our investigation we find arguments that cast doubt on the applicability of the TBA in this case. In a second application by use of the spinon and anti-spinon particle basis we obtain completely different results. Only for anisotropy parameter Δ close to 0 we find that D ( T ) is a monotonously decaying function of temperature. For Δ close to 1 the behaviour is entirely different showing a finite temperature maximum. Also for the isotropic antiferromagnetic chain (Δ=1) the results for D ( T ) are finite for T =0 as well as for T >0 with an infinite positive slope at T =0.