Majorana fermions at the edge of superconducting islands
Majorana fermions at the edge of superconducting islands
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DOI：
10.1103/physrevb.92.075432
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发表时间：
2015-08-21
影响因子：
3.7
通讯作者：
Nori, Franco
中科院分区：
文献类型：
--
作者：
Akzyanov, R. S.;Rakhmanov, A. L.;Nori, Franco
我们研究了位于磁场中拓扑绝缘体表面的超导岛边缘的电子态的特性。在这样的系统中，如果岛上有奇数个涡旋（或奇数多涡旋涡度），就会出现马约拉纳费米子；否则，就不存在马约拉纳州。马约拉纳态成对出现：一个态位于涡核附近，另一个态位于岛边缘。我们详细分析了由单个涡旋穿过的岛边缘的马约拉纳费米子的鲁棒性。如果优化系统参数，马约拉纳费米子与边缘第一激发态之间的能隙与拓扑绝缘体表面感应的超导能隙的量级相同。马约拉纳费米子态对栅极电压变化的稳定性及其对磁场的敏感性允许人们通过实验将边缘马约拉纳费米子与传统的狄拉克费米子区分开。
We investigate the properties of electron states localized at the edge of a superconducting island placed on the surface of a topological insulator in a magnetic field. In such systems, Majorana fermions emerge if an odd number of vortices (or odd multivortex vorticity) is hosted by the island; otherwise, no Majorana states exist. Majorana states emerge in pairs: one state is localized near the vortex core, and another at the island edge. We analyze in detail the robustness of Majorana fermions at the edge of the island threaded by a single vortex. If the system parameters are optimized, the energy gap between the Majorana fermion and the first excited state at the edge is of the order of the superconducting gap induced on the surface of the topological insulator. The stability of the Majorana fermion state against a variation of the gate voltage and its sensitivity to the magnetic field allows one to experimentally distinguish the edge Majorana fermion from conventional Dirac fermions.