Optimal topological spin pump
Optimal topological spin pump
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DOI：
10.1103/physrevb.82.161303
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发表时间：
2010-05
影响因子：
3.7
通讯作者：
D. Meidan;T. Micklitz;P. Brouwer
中科院分区：
文献类型：
--
作者：
D. Meidan;T. Micklitz;P. Brouwer
我们研究了最近引进的由一族具有时间反转限制的一维体绝缘体组成的泵浦。我们发现，这些泵浦的散射矩阵被拓扑指数二分化。我们证明了这种由非平凡拓扑指数表征的泵浦允许量子自旋的无声泵浦，即使在没有自旋守恒的情况下也是如此。这一区别揭示了二维时间反转不变绝缘体的分类。
We study the recently introduced ${\mathbb Z}_2$ pump consisting of a family of one-dimensional bulk insulators with time reversal restriction on the pumping cycle. We find that the scattering matrices of these pumps are dichotomized by a topological index. We show that the class of pumps characterized by a nontrivial topological index allows, in contrast to its topologically trivial counterpart, for the noiseless pumping of quantized spin, even in the absence of spin conservation. This distinction sheds light on the ${\mathbb Z}_2$ classification of two-dimensional time reversal invariant insulators.