High-temperature Majorana zero modes

TL;DR

This paper demonstrates that unpaired Majorana zero modes can exist at the vortex cores in a high-temperature topological superconductor interface, potentially enabling robust quantum computing applications at elevated temperatures.

Contribution

It introduces a new platform for high-temperature Majorana zero modes using a topological insulator and twisted cuprate superconductor interface, supported by general arguments and numerical simulations.

Findings

Majorana zero modes occur at vortex cores in the proposed heterostructure.

These modes can persist up to temperatures close to 90K.

The interface can host a fully gapped topological superconductor with large protection gaps.

Abstract

We employ general arguments and numerical simulations to show that unpaired Majorana zero modes can occur in cores of Abrikosov vortices at the interface between a three-dimensional topological insulator, such as Bi$_2$Se$_3$, and a twisted bilayer of high-$T_c$ cuprate superconductor, such as Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. When the twist angle is close to $45^{\rm o}$ the latter forms a fully gapped topological superconductor up to temperatures approaching its native $T_c\simeq 90$K. Majorana zero modes in these structures will persist up to unprecedented high temperatures and, depending on the quality of the interface, may be protected by gaps with larger magnitudes than other candidate systems.