Theory of the Josephson current on a magnetically doped topological insulator
Theory of the Josephson current on a magnetically doped topological insulator
复制标题
DOI：
10.1103/physrevb.100.104518
复制
发表时间：
2019-06
影响因子：
3.7
通讯作者：
T. Toki;Sho Nakosai;Yukio Tanaka;Y. Kawaguchi
中科院分区：
文献类型：
--
作者：
T. Toki;Sho Nakosai;Yukio Tanaka;Y. Kawaguchi
磁掺杂拓扑绝缘体表面的邻近感生超导态可以承载手征Majorana模。我们考虑在该系统中的约瑟夫森结与变化的化学势，这驱动的诱导超导态的拓扑相变以及在表面状态的金属-绝缘体的转变。根据Andreev反射系数，用McMillan的绿色函数方法解析计算了局域态密度和约瑟夫森电流。我们发现，虽然约瑟夫森电流的幅度大大增强时，表面状态从绝缘到金属的变化，其温度依赖性急剧变化的拓扑相变点，反映了外观的手性马约拉纳模式。
Proximity induced superconducting states in the surface of magnetically doped topological insulators can host chiral Majorana modes. We consider a Josephson junction in that system with changing the chemical potential, which drives a topological phase transition in the induced superconducting states as well as a metal-insulator transition in the surface states. The local density of states and the Josephson current are analytically calculated by McMillan's Green's function method in terms of the Andreev reflection coefficient. We show that although the magnitude of the Josephson current is greatly enhanced when the surface state changes from insulating to metallic, its temperature dependence drastically changes at the topological phase transition point, reflecting the appearance of the chiral Majorana modes.