High-Temperature Majorana Corner States

TL;DR

This paper demonstrates the emergence of Majorana corner states in a 2D topological insulator with an $s_$-wave superconductor, providing a high-temperature platform for non-Abelian quasiparticles.

Contribution

It introduces a new mechanism for Majorana corner states in 2D topological insulators with $s_$-wave pairing, validated by a bulk invariant and edge argument.

Findings

Majorana Kramers pairs appear at each corner of the 2D topological insulator.

Phase diagram highlights the influence of bulk parameters and edge orientations.

Proposes experimental realizations in candidate materials.

Abstract

Majorana bound states often occur at the end of 1D topological superconductor or at the $\pi$ Josephson junction mediated by a helical edge state. Validated by a new bulk invariant and an intuitive edge argument, we show the emergence of one Majorana Kramers pair at each corner of a square-shaped 2D topological insulator proximitized by an $s_\pm$-wave (e.g., Fe-based) superconductor. We obtain a phase diagram that emphasizes the roles of bulk parameters and edge orientations. We propose several experimental realizations in lattice-matched candidate materials. Our scheme offers a high-temperature platform for exploring higher-order non-Abelian quasiparticles.