Kawakami Takuto, Hu Xiao
International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Tsukuba 305-0044, Japan.
Phys Rev Lett. 2015 Oct 23;115(17):177001. doi: 10.1103/PhysRevLett.115.177001. Epub 2015 Oct 22.
In terms of the Bogoliubov-de Gennes approach, we investigate the Majorana bound state (MBS) in a vortex of proximity-induced superconductivity on the surface of a topological insulator. Mapping out the local density of states (LDOS) of quasiparticle excitations as a function of energy and distance from the vortex center, it is found that the spectral distribution evolves from a V shape to a Y shape with the emergence of a MBS upon variation of the chemical potential, consistent with the STM/STS measurement in a very recent experiment [Xu et al., Phys. Rev. Lett. 114, 017001 (2015)] on a Bi(2)Te(3) thin layer on the top of NbSe(2). Moreover, we demonstrate that there is a checkerboard-type pattern in the relative LDOS between the spin-up and -down channels, where the quantum mechanical wave function of the MBS manifests itself clearly as a single quantum state. Therefore, a spin-resolved STM/STS technique is expected to be able to provide phase-sensitive evidence for a MBS in the vortex core of a topological superconductor.
根据博戈留波夫 - 德热纳方法,我们研究了拓扑绝缘体表面近邻诱导超导涡旋中的马约拉纳束缚态(MBS)。通过绘制准粒子激发的局域态密度(LDOS)作为能量和距涡旋中心距离的函数,发现随着化学势的变化,当出现MBS时,光谱分布从V形演变为Y形,这与最近在NbSe₂顶部的Bi(2)Te(3)薄层上进行的实验[Xu等人,《物理评论快报》114, 017001 (2015)]中的扫描隧道显微镜/扫描隧道谱(STM/STS)测量结果一致。此外,我们证明在自旋向上和向下通道之间的相对LDOS中存在棋盘型图案,其中MBS的量子力学波函数清晰地表现为单个量子态。因此,自旋分辨的STM/STS技术有望能够为拓扑超导体涡旋核心中的MBS提供相敏证据。