High temperature spin-triplet topological superconductivity in K2Cr3As3

TL;DR

This paper reviews the discovery of K2Cr3As3 as a high-temperature spin-triplet superconductor with potential for topological quantum computing, emphasizing its multiple phases and proximity to a ferromagnetic quantum critical point.

Contribution

It establishes K2Cr3As3 as a high-temperature spin-triplet superconductor with topological properties, highlighting its unique phase features and criticality proximity.

Findings

K2Cr3As3 is a spin-triplet superconductor with T_c up to 6.5 K.

The material exhibits multiple superconducting phases.

Its proximity to a ferromagnetic quantum critical point may enhance T_c.

Abstract

Spin-triplet superconductors are novel materials capable of harboring Majorana bound states that can be used in topological quantum computing. However, such bulk materials are still rare. Here we review the results that established K2Cr3As3 as a spin-triplet superconductor with transition temperature T_c as high as 6.5 K. We focus on the multiple-phases feature, and its exquisite distance to a ferromagnetic quantum critical point which is likely responsible for the high T_c. We touch on the topological aspect of the superconducting state, and suggest that it is a new route to the technical implementation using a topological spin-triplet superconductor at the highest temperature ever.