Quantum multicriticality in disordered Weyl semimetals
Quantum multicriticality in disordered Weyl semimetals
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无序外尔半金属的量子多临界性
DOI：
10.1103/physrevb.97.045129
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发表时间：
2017-10
影响因子：
3.7
通讯作者：
Ryuichi Shindou
中科院分区：
文献类型：
--
作者：
Xunlong Luo;Baolong Xu;Tomi Ohtsuki;Ryuichi Shindou
在固态材料的电子能带结构中，两个具有线性色散的能带接触点在动量空间中成对出现。当它们相互湮灭时，系统会经历从三维韦尔半金属（WSM）相到带绝缘体相（例如陈带绝缘体（CI）相）的量子相变。相变由动量空间中类似“磁偶极子”物体的新临界理论来描述。在本文中，我们揭示了该临界理论具有一种新颖的无序驱动的量子多临界点，该多临界点由三个量子相、重正化 WSM 相、CI 相和扩散金属 (DM) 相组成。基于重正化群论证，我们首先阐明了量子多临界点处的能带接触点周围的标度特性以及这三个相之间的所有相边界。基于局域长度、态密度和临界电导分布的数值计算，我们接下来证明具有有限零能量态密度（zDOS）的CI相和DM相之间的局域-离域转变属于普通3D酉类。同时，零 zDOS 的 Chern 绝缘体相和重正化 Weyl 半金属 (WSM) 相之间的局域-离域转变是直接相变，其临界指数 $\nu=0.80\pm 0.01$。我们通过批判理论的重正化群分析来解释这些数值结果。
In electronic band structure of solid state material, two band touching points with linear dispersion appear in pair in the momentum space. When they annihilate with each other, the system undergoes a quantum phase transition from three-dimensional Weyl semimetal (WSM) phase to a band insulator phase such as Chern band insulator (CI) phase. The phase transition is described by a new critical theory with a `magnetic dipole' like object in the momentum space. In this paper, we reveal that the critical theory hosts a novel disorder-driven quantum multicritical point, which is encompassed by three quantum phases, renormalized WSM phase, CI phase, and diffusive metal (DM) phase. Based on the renormalization group argument, we first clarify scaling properties around the band touching points at the quantum multicritical point as well as all phase boundaries among these three phases. Based on numerical calculations of localization length, density of states and critical conductance distribution, we next prove that a localization-delocalization transition between the CI phase with a finite zero-energy density of states (zDOS) and DM phase belongs to an ordinary 3D unitary class. Meanwhile, a localization-delocalization transition between the Chern insulator phase with zero zDOS and a renormalized Weyl semimetal (WSM) phase turns out to be a direct phase transition whose critical exponent $\nu=0.80\pm 0.01$. We interpret these numerical results by a renormalization group analysis on the critical theory.
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影响因子：
4.4
作者：
K. Kajita;N. Tajima;A. Ebina-Tajima;Y. Nishio
通讯作者：
K. Kajita;N. Tajima;A. Ebina-Tajima;Y. Nishio
影响因子：
3.7
作者：
Hassan Shapourian;T. Hughes
通讯作者：
Hassan Shapourian;T. Hughes
DOI：
--
发表时间：
2011
期刊：
--
影响因子：
--
作者：
Xiangang Wan;Ari M. Turner;A. Vishwanath
通讯作者：
Xiangang Wan;Ari M. Turner;A. Vishwanath
影响因子：
56.9
作者：
Xu, Su-Yang;Belopolski, Ilya;Hasan, M. Zahid
通讯作者：
Hasan, M. Zahid
外尔半金属 TaAs 的实验发现
影响因子：
12.5
作者：
Lv, B. Q.;Weng, H. M.;Ding, H.
通讯作者：
Ding, H.