Pressure-induced superconductivity at 32 K in MoB2

Cuiying Pei; Jianfeng Zhang; Qi Wang; Yi Zhao; Lingling Gao; Chunsheng Gong; Shangjie Tian; Ruitao Luo; Mingtao Li; Wenge Yang; Zhong-Yi Lu; Hechang Lei; Kai Liu; Yanpeng Qi

doi:10.1093/nsr/nwad034

Pressure-induced superconductivity at 32 K in MoB₂

Natl Sci Rev. 2023 Feb 14;10(5):nwad034. doi: 10.1093/nsr/nwad034. eCollection 2023 May.

Authors

Cuiying Pei¹, Jianfeng Zhang², Qi Wang^{1

2

3}, Yi Zhao¹, Lingling Gao¹, Chunsheng Gong², Shangjie Tian², Ruitao Luo², Mingtao Li⁴, Wenge Yang⁴, Zhong-Yi Lu², Hechang Lei², Kai Liu², Yanpeng Qi^{1

3

5}

Affiliations

¹ School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
² Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China.
³ ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, China.
⁴ Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China.
⁵ Shanghai Key Laboratory of High-resolution Electron Microscopy, ShanghaiTech University, Shanghai 201210, China.

Abstract

Since the discovery of superconductivity in MgB₂ (T_c ∼ 39 K), the search for superconductivity in related materials with similar structures or ingredients has never stopped. Although about 100 binary borides have been explored, only a few of them show superconductivity with relatively low T_c. In this work, we report the discovery of superconductivity up to 32 K, which is the highest T_c in transition-metal borides, in MoB₂ under pressure. The T_c of MoB₂ in the α phase can be well explained by theoretical calculations in the framework of electron-phonon coupling. Furthermore, the coupling between the d electrons of Mo and the out-of-plane Mo-phonon modes are the main driving force of the 32 K superconductivity of MoB₂. Our study sheds light on the exploration of high-T_c superconductors in transition metal borides.

Keywords: borides; high pressure; superconductivity.