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arXiv 1011.5166cond-mat.mes-hall
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拓扑绝缘体环中的束缚态和持续电流

Bound states and persistent currents in topological insulator rings

Paolo Michetti, Patrik Recher

摘要:

以碲化汞量子阱的四带模型为具体例子,对二维拓扑绝缘体中Aharonov-Bohm(AB)环的束缚态谱进行了理论分析。我们解析地计算了环形螺旋边缘态及其谱,以及从体谱中演化出来的束缚态随外加磁通量和环尺寸的变化。我们还分析了自旋相关的持续电流,它可以用来测量单个电子的自旋。我们进一步考虑到Rashba自旋轨道相互作用,混合的自旋状态,并得出其对环谱的影响。环态的通量可调谐性允许束缚电子的边缘自由度和自旋自由度的相干混合,这可以用于拓扑绝缘体环中的量子信息处理。

英文摘要:

We analyze theoretically the bound state spectrum of an Aharonov Bohm (AB) ring in a two-dimensional topological insulator using the four-band model of HgTe-quantum wells as a concrete example. We calculate analytically the circular helical edge states and their spectrum as well as the bound states evolving out of the bulk spectrum as a function of the applied magnetic flux and dimension of the ring. We also analyze the spin-dependent persistent currents, which can be used to measure the spin of single electrons. We further take into account the Rashba spin-orbit interaction which mixes the spin states and derive its effect on the ring spectrum. The flux tunability of the ring states allows for coherent mixing of the edge- and the spin degrees of freedom of bound electrons which could be exploited for quantum information processing in topological insulator rings.

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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