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arXiv 1409.7735cond-mat.mes-hall
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量子点和量子环中Majorana态的探测

Probing Majorana-like states in quantum dots and quantum rings

Benedikt Scharf, Igor Žutić

摘要:

工程手性$p$波超导半导体结构提供了迷人的方式来获得和研究马约拉纳模式在凝聚态的背景下。本文从理论上研究了量子点和量子环中的手征$p$波超导电性。使用解析和数值方法,我们计算了这些结构中的准粒子激发谱和相应的激发振幅和电荷密度。在拓扑结构中,我们可以观察到量子点和量子环中的手征边缘模,它们局域在边界上,具有有限的能量。通过施加从量子环中排出的磁场,但其产生的通量是$Φ_0/2=π\hbar/e$的奇数倍,马约拉纳模式,即具有零能量和零电荷密度的(近似)简并边缘模式,在拓扑机制中成为可能。此外,我们调查有限尺寸的影响,分裂这些退化的边缘模式,以及渗透到超导区域的磁场的效果,在某些情况下仍然可以支持边缘模式与近似为零的能量和电荷。

英文摘要:

Engineering chiral $p$-wave superconductivity in semiconductor structures offers fascinating ways to obtain and study Majorana modes in a condensed matter context. Here, we theoretically investigate chiral $p$-wave superconductivity in quantum dots and quantum rings. Using both analytical as well as numerical methods, we calculate the quasiparticle excitation spectra in these structures and the corresponding excitation amplitudes and charge densities. In the topological regime, we can observe the chiral edge modes localized at the boundaries and possessing finite energy in quantum dots and quantum rings. By applying a magnetic field which is expelled from the quantum ring, but which creates a flux that is an odd integer multiple of $Φ_0/2=π\hbar/e$, Majorana modes, that is, (approximately) degenerate edge modes with zero energy and zero charge density, become possible in the topological regime. Furthermore, we investigate finite-size effects that split these degenerate edge modes as well as the effect of a magnetic field penetrating into the superconducting region that can under certain circumstances still support edge modes with approximately zero energy and charge.

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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