Chiral Majorana modes on electrically gated high Tc Topological Superconductors

Majorana edge modes were detected by observation of half-integer conductivity in a magnetic topological insulator/superconductor (MTI/SC) heterostructure [1]. Recently proposed systems which are compatible with standard semiconductor processing are the most promising schemes for braiding Majorana modes. However, identifying Majorana zero modes experimentally has been challenging mostly because of the small pairing gap of s-wave SCs. A heterostructure between an anomalous quantum Hall insulator and a high Tc d-wave superconductor with a large pairing gap may offer a more feasible approach for implementing Majorana zero modes.

In this work, we study topological properties of a gated d-wave (MTI/SC) heterostructure. The phase diagram of the system is obtained by employing the Kubo formula. The existence of Majorana edge modes in the presence of electrical gating has been shown in d-wave topological superconductors. A Green's function formalism has been employed for the detection of Majorana edge modes and their localization properties have been investigated.

1.He, Q. L. et al. Chiral Majorana fermion modes in a quantum anomalous Hall insulator–superconductor structure. Science 357, 294–299 (2017).