2020/08/31 by Shingo Kobayashi, Akira Furusaki · 1 citation
Physics and Astronomy · #cond-mat.supr-con #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.102.180505
published as Phys. Rev. B 102, 180505 (2020) · 10 pages, 4 figures
arxiv created 2020/11/11 · arxiv updated 2020/11/25
The interplay of time-reversal and n-fold rotation symmetries (n=2,4,6) is known to bring a new class of topological crystalline insulators (TCIs) having n surface Dirac cones due to surface rotation anomaly. We show that the proximity-induced s-wave superconductivity on the surface of these TCIs yields a topological superconducting phase in which two Majorana zero modes are bound to a vortex, and that n-fold rotation symmetry (n=2,4,6) enriches the topological classification of a superconducting vortex from ℤ2 to ℤ2×ℤ2. Using a model of a three-dimensional high-spin topological insulator with s-wave superconductivity and two-fold rotation symmetry, we show that, with increasing chemical potential, the number of Majorana zero modes at one end of a vortex changes as 2→1→0 through two topological vortex phase transitions. In addition, we show that additional magnetic-mirror symmetry further enhances the topological classification to ℤ × ℤ