Wang Hao, Yin Xin-Zhu, Liu Yang, Li Ya-Ping, Ni Mei-Yan, Jiao Na, Lu Hong-Yan, Zhang Ping
School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China.
Institute of Applied Physics and Computational Mathematics, Beijing 100088, China.
Phys Chem Chem Phys. 2023 Aug 23;25(33):22171-22178. doi: 10.1039/d3cp02316h.
The discovery of highly crystalline two-dimensional (2D) superconductors provides a new alluring branch for exploring the fundamental significances. Based on first-principles calculations, we predict a new kind of 2D stable material WC, which is a semimetal but not a superconductor because of the weak electron-phonon coupling (EPC) strength. After hydrogenation, WCH possesses the intrinsic metallic properties with a large density of states (DOS) at the Fermi energy (). More interestingly, the EPC strength is greatly enhanced after hydrogenation and the calculated critical temperature () is 40.5 K. Furthermore, the compressive strain can obviously soften the low-frequency phonons and enhance the EPC strength. Then, the of WCH can be increased from 40.5 K to 49.1 K with -4% compressive strain. This work paves the way for providing a new platform for 2D superconductivity.
高结晶二维（2D）超导体的发现为探索其基本意义提供了一个新的诱人分支。基于第一性原理计算，我们预测了一种新型的二维稳定材料WC，由于其电子-声子耦合（EPC）强度较弱，它是一种半金属而非超导体。氢化后，WCH具有本征金属特性，在费米能（）处具有较大的态密度（DOS）。更有趣的是，氢化后EPC强度大大增强，计算得到的临界温度（）为40.5K。此外，压缩应变可以明显软化低频声子并增强EPC强度。然后，在-4%的压缩应变下，WCH的可以从40.5K提高到49.1K。这项工作为二维超导提供了一个新平台铺平了道路。
