npj:拓扑超导体的“从头算”—Wannier函数的威力
海归学者发起的公益学术平台
分享信息,整合资源
交流学术,偶尔风月
来自美国犹他大学材料科学与工程系刘锋教授和清华大学高等研究院刘铮教授带领的,包括中国海洋大学、清华大学、山东大学和韩国Pohang大学在内的国际合作团队,利用用瓦尼尔函数为基矢构造能带结构,在考虑Rashba自旋轨道耦合、塞曼分裂和电子-声子耦合的情况下,构建了针对特定超导材料,即锰掺杂碲化锗单层材料(Ge1-xMnxTe)拓扑超导相的第一性原理相图。通过自洽求解基于BdG哈密顿量的BdG方程,作者既估算了超导临界转变温度和临界磁场强度,又通过计算拓扑不变量和手性马约拉纳边缘模式来表征了拓扑超导相。计算得到的相图表明,Ge1-xMnxTe的空穴浓度为~7.4×1013 cm-2时,单层GeTe在~120 mK以下变为超导体,Mn浓度为x~0.015%的Ge1-xMnxTe在~40 mK下是D类拓扑超导体,这可用其被非零的陈数和手性马约拉纳边缘模式表征。
该工作为利用第一性原理计算预测拓扑超导体材料和量化拓扑超导的实现条件提供了可靠方案,并对相关实验研究具有重要的指导意义。
该文近期发表于npj Computational Materials 7: 44 (2021),英文标题与摘要如下,点击左下角“阅读原文”可以自由获取论文PDF。
Prediction of intrinsic topological superconductivity in Mn-doped GeTe monolayer from first-principles
Xiaoming Zhang, Kyung-Hwan Jin, Jiahao Mao, Mingwen Zhao, Zheng Liu* & Feng Liu*
The recent discovery of topological superconductors (TSCs) has sparked enormous interest. The realization of TSC requires a delicate tuning of multiple microscopic parameters, which remains a great challenge. Here, we develop a first-principles approach to quantify realistic conditions of TSC by solving self-consistently Bogoliubov-de Gennes equation based on a Wannier function construction of band structure, in presence of Rashba spin-orbit coupling, Zeeman splitting and electron-phonon coupling. We further demonstrate the power of this method by predicting the Mn-doped GeTe (Ge1-xMnxTe) monolayer – a well-known dilute magnetic semiconductor showing superconductivity under hole doping – to be a Class D TSC with Chern number of -1 and chiral Majorana edge modes. By constructing a first-principles phase diagram in the parameter space of temperature and Mn concentration, we propose the TSC phase can be induced at a lower-limit transition temperature of ~40 mK and the Mn concentration of x~0.015%. Our approach can be generally applied to TSCs with a phonon-mediated pairing, providing useful guidance for future experiments.
本文系网易新闻·网易号“各有态度”特色内容
媒体转载联系授权请看下方
最新评论
推荐文章
作者最新文章
你可能感兴趣的文章
Copyright Disclaimer: The copyright of contents (including texts, images, videos and audios) posted above belong to the User who shared or the third-party website which the User shared from. If you found your copyright have been infringed, please send a DMCA takedown notice to [email protected]. For more detail of the source, please click on the button "Read Original Post" below. For other communications, please send to [email protected].
版权声明:以上内容为用户推荐收藏至CareerEngine平台,其内容(含文字、图片、视频、音频等)及知识版权均属用户或用户转发自的第三方网站,如涉嫌侵权,请通知[email protected]进行信息删除。如需查看信息来源,请点击“查看原文”。如需洽谈其它事宜,请联系[email protected]。
版权声明:以上内容为用户推荐收藏至CareerEngine平台,其内容(含文字、图片、视频、音频等)及知识版权均属用户或用户转发自的第三方网站,如涉嫌侵权,请通知[email protected]进行信息删除。如需查看信息来源,请点击“查看原文”。如需洽谈其它事宜,请联系[email protected]。