Majorana corner states in a twodimensional magnetic topological insulator on a hightemperature superconductor
Abstract
Conventional n dimensional topological superconductors (TSCs) have protected gapless (n 1 ) dimensional boundary states. In contrast to this, secondorder TSCs are characterized by topologically protected gapless (n 2 ) dimensional states with the usual gapped (n 1 ) boundaries. Here, we study a secondorder TSC with a twodimensional (2D) magnetic topological insulator proximity coupled to a hightemperature superconductor, where Majorana bound states (MBSs) are localized at the corners of a square sample with gapped edge modes. Due to the mirror symmetry of the hybrid system considered here, there are two MBSs at each corner for both cases: d wave and s_{±}wave superconducting pairing. We present the corresponding topological phase diagrams related to the role of the magnetic exchange interaction and the pairing amplitude. A detailed analysis, based on edge theory, reveals the origin of the existence of MBSs at the corners of the 2D sample, which results from the sign change of the Dirac mass emerging at the intersection of any two adjacent edges due to pairing symmetry. Possible experimental realizations are discussed. Our proposal offers a promising platform for realizing MBSs and performing possible nonAbelian braiding in 2D systems.
 Publication:

Physical Review B
 Pub Date:
 December 2018
 DOI:
 10.1103/PhysRevB.98.245413
 arXiv:
 arXiv:1806.07002
 Bibcode:
 2018PhRvB..98x5413L
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 11 pages, 9 figures. Published version