Majorana Corner Modes in a High-Temperature Platform

We introduce two-dimensional topological insulators in proximity to high-temperature cuprate or iron based superconductors as high-temperature platforms of Majorana Kramers pairs of zero modes. The proximity-induced pairing at the helical edge state of the topological insulator serves as a Dirac mass, whose sign changes at the sample corner because of the pairing symmetry of high-Tc superconductors. This sign changing naturally creates at each corner a pair of Majorana zero modes protected by time-reversal symmetry. Conceptually, this is a topologically trivial superconductor-based approach for Majorana zero modes. We provide quantitative criteria and suggest candidate materials for this proposal.[Reference: Phys. Rev. Lett. 121, 096803 (2018)]