Chiral gauge field and axial anomaly in a Weyl semimetal
Chiral gauge field and axial anomaly in a Weyl semimetal
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DOI：
10.1103/physrevb.87.235306
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发表时间：
2013-06-10
影响因子：
3.7
通讯作者：
Qi, Xiao-Liang
中科院分区：
文献类型：
--
作者：
Liu, Chao-Xing;Ye, Peng;Qi, Xiao-Liang
外尔费米子是（3 + 1）维的双组分手征费米子。当耦合到规范场时，外尔费米子已知具有轴向异常，这意味着左手和右手外尔费米子的当前守恒不能单独保持。最近，外尔费米子在凝聚态系统中被提出，命名为“外尔半金属”。“本文提出了磁掺杂拓扑绝缘体中的Weyl半金属相，并研究了该系统中的轴向异常。我们提出，在这个系统中的磁涨落起着“手征规范场”的作用，最低限度地耦合到Weyl费米子与两个手征相反的电荷。我们研究了这个系统的反常方程，并讨论了它的物理后果，包括铁磁涡旋线中的一维手征模，以及一种新的等离子体-磁振子耦合。
Weyl fermions are two-component chiral fermions in (3 + 1) dimensions. When coupled to a gauge field, the Weyl fermion is known to have an axial anomaly, which means the current conservation of the left-handed and right-handed Weyl fermions cannot be preserved separately. Recently, Weyl fermions have been proposed in condensed-matter systems named "Weyl semimetals." In this paper we propose a Weyl semimetal phase in magnetically doped topological insulators, and study the axial anomaly in this system. We propose that the magnetic fluctuation in this system plays the role of a "chiral gauge field" which minimally couples to the Weyl fermions with opposite charges for two chiralities. We study the anomaly equation of this system and discuss its physical consequences, including one-dimensional chiral modes in a ferromagnetic vortex line, and a novel plasmon-magnon coupling.