Acoustic plasmons in type-I Weyl semimetals

Article

关键词: SUPERCONDUCTIVITY;    SEMICONDUCTORS;    DISCOVERY;    METALS;   

DOI  :  10.1103/PhysRevB.103.205201

来源: SCIE

【 摘 要 】

Massless chiral fermions emergent in inversion symmetry-breaking Weyl semimetals (WSMs) reside in the vicinity of multiple low-symmetry nodes and thus acquire strongly anisotropic dispersion. We investigate the longitudinal electromagnetic modes of two-component degenerate Weyl plasma relevant to the realistic band structure of type-I WSM. We show that the actual spectrum of three-dimensional collective density excitations in the TaAs family of WSM is gapless due to emergence of acoustic plasmons corresponding to out-of-phase oscillations of the plasma components. These modes exist around the [001] crystallographic direction and are weakly damped, due to large difference in the Weyl velocities of the W-1 and W-2 quasiparticles propagating along [001]. We show that acoustic plasmons can manifest themselves as slow beatings of electric potential superimposed on fast plasmonic oscillations upon charge relaxation. The revealed acoustic modes can stimulate purely electronic superconductivity, collisionless plasmon instabilities, and formation of Weyl soundarons.

【 授权许可】

Free