Driven isotropic Heisenberg spin chain with arbitrary boundary twisting angle: exact results.
Driven isotropic Heisenberg spin chain with arbitrary boundary twisting angle: exact results.
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具有任意边界扭转角度的驱动各向同性海森堡自旋链：精确结果。
DOI：
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发表时间：
2013
期刊：
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通讯作者：
G. M. Schütz
中科院分区：
文献类型：
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作者：
V. Popkov;D. Karevski;G. M. Schütz
我们考虑一个开放的各向同性海森堡量子自旋链，耦合在两端的边界水库极化在不同的方向，这建立了一个扭转梯度链。利用矩阵积方法，我们精确计算了具有N个位置的链在非平衡稳态下的磁化强度分布和磁化电流。磁化曲线是频率与扭转角θ成比例的谐波函数。位于扭转平面和正交方向上的磁化分量的电流表现出性质上的不同：对于固定且足够大的边界耦合，平面内稳态电流的比例为1/N^{2}，并且随着耦合的增加而消失，而横向电流随着耦合的增加而增加并饱和到2θ/N。
We consider an open isotropic Heisenberg quantum spin chain, coupled at the ends to boundary reservoirs polarized in different directions, which sets up a twisting gradient across the chain. Using a matrix product ansatz, we calculate the exact magnetization profiles and magnetization currents in the nonequilibrium steady state of a chain with N sites. The magnetization profiles are harmonic functions with a frequency proportional to the twisting angle θ. The currents of the magnetization components lying in the twisting plane and in the orthogonal direction behave qualitatively differently: In-plane steady-state currents scale as 1/N^{2} for fixed and sufficiently large boundary coupling, and vanish as the coupling increases, while the transversal current increases with the coupling and saturates to 2θ/N.