High-Temperature Majorana Corner States

TLDR

Majorana bound states typically appear at the ends of 1D topological superconductors or at π Josephson junctions mediated by helical edge states. The study aims to experimentally realize high‑temperature Majorana corner states. The authors propose using lattice‑matched candidate materials to achieve this. They show that a square‑shaped 2D topological insulator proximitized by an s±‑wave superconductor hosts a Majorana Kramers pair at each corner, present a phase diagram highlighting bulk and edge effects, and offer a high‑temperature platform for higher‑order non‑Abelian quas.

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.