Local density of states in two-dimensional topological superconductors under a magnetic field: Signature of an exterior Majorana bound state

摘要: We study quasiparticle states on a surface of topological insulator (TI) with proximity-induced superconductivity under an external magnetic field. An applied field creates two Majorana bound states: vortex state localized inside core and exterior along circle centered at the core. calculate spin-resolved local density (LDOS) demonstrate that shrinking radius state, predicted in R. S. Akzyanov et al., Phys. Rev. B 94, 125428 (2016), strong can be seen LDOS without smeared out by nonzero-energy states. The further reveals spin is strongly spin-polarized. Accordingly, induced odd-frequency spin-triplet pairs are found to spin-polarized as well. In order detect states, however, Fermi energy should closed Dirac point avoid contributions from continuum levels. also different two-dimensional topological-superconducting system where electron gas spin-orbit coupling sandwiched between $s$-wave superconductor ferromagnetic insulator. show tuned However, contrary results TI surface, neither nor conclude polarization attributed Landau level, which characteristic for systems Dirac-like dispersion.