Discovery of the high-entropy carbide ceramic topological superconductor candidate (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C

TL;DR

This paper reports the discovery of superconductivity and topological properties in a high-entropy carbide ceramic, expanding the understanding of physical properties in high-entropy ceramics and their potential for superconductivity research.

Contribution

The study presents the first observation of superconductivity and topological features in a high-entropy carbide ceramic, supported by theoretical calculations and experimental validation.

Findings

Superconductivity observed at around 2.35 K in (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C

Presence of six type-II Dirac points in the material

Superconductivity remains stable under pressure

Abstract

High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements. Material design and property tailoring possibilities emerge from this new class of materials. Here, we report the discovery of superconductivity around 2.35 K and topological properties in the (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C high-entropy carbide ceramic (HECC), which has not been observed before in any of the investigated HECC. Density functional theory calculations showed that six type-II Dirac points exist in (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C, which mainly contributed from the t2g orbitals of transition metals and the p orbitals of C. Due to the stability of the structure, we also observed robust superconductivity under pressure in this HEC superconductor. This study expands the physical properties of HECs, which may become a new material platform for superconductivity research, especially for studying the coupling between superconductivity and topological physics.