Dynamical chiral magnetic current and instability in Weyl semimetals
Dynamical chiral magnetic current and instability in Weyl semimetals
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外尔半金属的动态手性磁流和不稳定性
DOI：
10.1103/physrevb.107.014302
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发表时间：
2023
影响因子：
3.7
通讯作者：
Nishida Yusuke
中科院分区：
文献类型：
--
作者：
Amitani Tatsuya;Nishida Yusuke
Weyl半金属实现了在能量和动量空间中分离的两个Weyl结点的无质量相对论性费米子，其低能物理由轴向规范常数的Dirac费米子描述。在此，我们基于有效场论和手征动力学理论研究了它们的电磁线性响应。尽管在Pauli-Villars正则化下，静态手征磁效应被Chern-Simons电流所抵消，但对于均匀磁场，动态磁场能够驱动电流沿其方向运动，并且总的输运电荷与温度和化学势无关。我们还在弛豫时间近似中引入了耗散，并研究了Weyl节点布居偏离平衡时集体激发与麦克斯韦电磁场的耦合。它们在低频和长波长的色散关系仅由电、手征磁性和反常的霍尔电导决定，这些电导预测了导致各向异性产生沿Weyl节点分离方向的电磁波的不稳定模。
Weyl semimetals realize massless relativistic fermions with two Weyl nodes separated in energy and momentum space, whose low-energy physics is described by Dirac fermions with an axial gauge constant. Here, we study their electromagnetic linear responses based on the effective field theory and on the chiral kinetic theory. Although the static chiral magnetic effect is canceled by the Chern-Simons current under the Pauli-Villars regularization, a dynamical magnetic field is found capable of driving an electric current along its direction, with the total transported charge being independent of temperature and chemical potential for a uniform field. We also incorporate dissipation in the relaxation-time approximation and study collective excitations coupled with Maxwell electromagnetic fields when Weyl node populations deviate from equilibrium. Their dispersion relations at low frequency and long wavelength are determined only by electric, chiral magnetic, and anomalous Hall conductivities, which predict unstable modes leading to anisotropic generation of electromagnetic waves oriented to the direction of Weyl node separation.
影响因子：
44.1
作者：
Armitage, N. P.;Mele, E. J.;Vishwanath, Ashvin
通讯作者：
Vishwanath, Ashvin