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arXiv 1102.0824cond-mat.str-el
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自旋梯系统的拓扑相、Majorana模和猝灭动力学

Topological phases, Majorana modes and quench dynamics in a spin ladder system

Wade DeGottardi, Diptiman Sen, Smitha Vishveshwara

摘要:

我们探索的显着特点的'Kitaev梯子',一个两条腿的梯子版本的自旋1/2 Kitaev模型的蜂窝晶格,通过将其映射到一个一维的费米p波超导系统。我们研究了非相互作用费米子系统的自旋相位和拓扑非平凡相位之间的联系,证明了自旋系统中全局Z2对称性的自发破缺与孤立Majorana模的存在之间的等价性。在Kitaev阶梯,我们调查的拓扑性质的系统在不同的部门,其特征在于存在或不存在的漩涡在每个plaquette的阶梯。我们表明,涡旋模式可以产生丰富的参数空间,调整到拓扑非平凡的阶段。我们引入了一个新的拓扑不变量,明确地确定存在的零能量马约拉纳模式在这样的阶段的边界。最后,我们讨论了动态淬火拓扑非平凡阶段之间的Kitaev阶梯,特别是淬火后的动态调谐通过量子临界点。

英文摘要:

We explore the salient features of the `Kitaev ladder', a two-legged ladder version of the spin-1/2 Kitaev model on a honeycomb lattice, by mapping it to a one-dimensional fermionic p-wave superconducting system. We examine the connections between spin phases and topologically non-trivial phases of non-interacting fermionic systems, demonstrating the equivalence between the spontaneous breaking of global Z2 symmetry in spin systems and the existence of isolated Majorana modes. In the Kitaev ladder, we investigate topological properties of the system in different sectors characterized by the presence or absence of a vortex in each plaquette of the ladder. We show that vortex patterns can yield a rich parameter space for tuning into topologically non-trivial phases. We introduce a new topological invariant which explicitly determines the presence of zero energy Majorana modes at the boundaries of such phases. Finally, we discuss dynamic quenching between topologically non-trivial phases in the Kitaev ladder, and in particular, the post-quench dynamics governed by tuning through a quantum critical point.

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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