Quantum Phase Transition and Entanglement in Topological Quantum Wires.
Quantum Phase Transition and Entanglement in Topological Quantum Wires.
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DOI：
10.1038/s41598-017-02717-w
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发表时间：
2017-06-05
影响因子：
4.6
通讯作者：
Kim KW
中科院分区：
文献类型：
--
作者：
Cho J;Kim KW
通过考察基态下的两位纠缠，研究了SU-Schrieffer-Heeger(SSH)模型的量子相变。结果表明，SSH模型的拓扑相变表现为局域纠缠的非解析性，对于有限偶数系统大小，局域纠缠的非解析性是不连续的，并且这种非解析性有一个拓扑起源。这种奇异性在非相互作用费米子的一维拓扑相变中具有普遍的性质。我们通过指出Kitaev链中表现出相同的非解析性的一个类似的量是局部电子密度，从而使这一点变得更加清楚。作为副产品，我们发现存在一种不同类型的相变，由此两位点纠缠的模式经历了突然的变化。这种转变仅以量子信息理论为特征，并不伴随着光谱带隙的关闭。我们分析了在相变点附近纠缠的标度行为。
We investigate the quantum phase transition of the Su-Schrieffer-Heeger (SSH) model by inspecting the two-site entanglements in the ground state. It is shown that the topological phase transition of the SSH model is signified by a nonanalyticity of local entanglement, which becomes discontinuous for finite even system sizes, and that this nonanalyticity has a topological origin. Such a peculiar singularity has a universal nature in one-dimensional topological phase transitions of noninteracting fermions. We make this clearer by pointing out that an analogous quantity in the Kitaev chain exhibiting the identical nonanalyticity is the local electron density. As a byproduct, we show that there exists a different type of phase transition, whereby the pattern of the two-site entanglements undergoes a sudden change. This transition is characterised solely by quantum information theory and does not accompany the closure of the spectral gap. We analyse the scaling behaviours of the entanglement in the vicinities of the transition points.