2021/04/25 by A. N. Afanasiev, A. A. Greshnov, Dmitry Svintsov +1
Materials Science · Physics and Astronomy · #2D Materials and Applications #Anisotropy #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Degenerate energy levels #Dirac fermion #Fermion #Geometry #Massless particle #Physics #Plasma #Plasma oscillation #Plasmon #Point reflection #Quantum electrodynamics #Quantum mechanics #Quasiparticle #Superconductivity #Symmetry (geometry) #Topological Materials and Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.103.205201
published as Phys. Rev. B 103, 205201 (2021) · 10 pages, 7 figures
arxiv created 2021/04/25 · openalex publication_date 2021/05/06 · arxiv updated 2021/05/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 W1 and W2 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.