Anomalous sound attenuation in Weyl semimetals in magnetic and pseudomagnetic fields
Anomalous sound attenuation in Weyl semimetals in magnetic and pseudomagnetic fields
复制标题
DOI：
10.1103/physrevb.103.214310
复制
发表时间：
2021-02
影响因子：
3.7
通讯作者：
P. Sukhachov;L. Glazman
中科院分区：
文献类型：
--
作者：
P. Sukhachov;L. Glazman
我们评估了受磁场或与应变相关的伪磁场影响的Weyl半金属材料的声衰减。由于节点内和节点间散射过程以及屏蔽的相互作用，这些场通常会降低声音吸收。在具有非对称Weyl节点的材料中(例如，不同的费米速度和/或弛豫时间)，可以发生对磁场和声波矢量的相对方向的非平凡依赖，即磁声二向色性。研究发现，外加应变感生的伪磁场也能激活Weyl材料的声二向色性。考虑到二向色性对场方向的依赖关系，二向色性可能导致声衰减相对于消失场的值有微弱的增强。
We evaluate the sound attenuation in a Weyl semimetal subject to a magnetic field or a pseudomagnetic field associated with a strain. Due to the interplay of intra- and inter-node scattering processes as well as screening, the fields generically reduce the sound absorption. A nontrivial dependence on the relative direction of the magnetic field and the sound wave vector, i.e., the magnetic sound dichroism, can occur in materials with nonsymmetric Weyl nodes (e.g., different Fermi velocities and/or relaxation times). It is found that the sound dichroism in Weyl materials can also be activated by an external strain-induced pseudomagnetic field. In view of the dependence on the field direction, the dichroism may lead to a weak enhancement of the sound attenuation compared with its value at vanishing fields.