论文标题
动力学手性磁电流和Weyl半法的不稳定性
Dynamical chiral magnetic current and instability in Weyl semimetals
论文作者
论文摘要
Weyl半学实现了无质量的相对论费物，其两个Weyl节点在能量和动量空间中分开，其低能物理学由轴向仪表常数的Dirac Fermions描述。在这里，我们根据有效的场理论和手性动力学理论研究了它们的电磁线性响应。尽管在Pauli-Villars正则化下的Chern-Simons电流取消了静态手性磁效应，但发现动态磁场能够沿其方向驱动电流，总的运输电荷与均匀场的温度和化学电位无关。我们还将耗散融合到松弛时间近似中，并研究集体激发与麦克斯韦电磁场相结合时，当Weyl节点群体偏离平衡时。它们在低频和长波长下的分散关系仅由电气，手性磁和异常的霍尔电导率决定，这预测了不稳定的模式，导致各向异性产生的电磁波朝向Weyl节点分离方向。
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.
