Entropy Wave Instability in Dirac and Weyl Semimetals

P. O. Sukhachov, E. V. Gorbar, and I. A. Shovkovy

Phys. Rev. Lett. 127, 176602 – Published 20 October 2021

Abstract

Hydrodynamic instabilities driven by a direct current are analyzed in 2D and 3D relativisticlike systems with the Dyakonov-Shur boundary conditions supplemented by a boundary condition for temperature. Besides the conventional Dyakonov-Shur instability for plasmons, we find an entropy wave instability in both 2D and 3D systems. The entropy wave instability is a manifestation of the relativisticlike nature of electron quasiparticles and a nontrivial role of the energy current in such systems. These two instabilities occur for the opposite directions of fluid flow. While the Dyakonov-Shur instability is characterized by the plasma frequency in 3D and the system size in 2D, the frequency of the entropy wave instability is tunable by the system size and the flow velocity.

Received 2 July 2021
Accepted 27 September 2021

DOI:https://doi.org/10.1103/PhysRevLett.127.176602

Physics Subject Headings (PhySH)

Hydrodynamic instabilities Plasma instabilities

Dirac semimetal Graphene Weyl semimetal

Hydrodynamics

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

P. O. Sukhachov ^1,*, E. V. Gorbar ^2,3, and I. A. Shovkovy ^4,5

¹Department of Physics, Yale University, New Haven, Connecticut 06520, USA
²Department of Physics, Taras Shevchenko National University of Kyiv, Kyiv 03022, Ukraine
³Bogolyubov Institute for Theoretical Physics, Kyiv 03143, Ukraine
⁴College of Integrative Sciences and Arts, Arizona State University, Mesa, Arizona 85212, USA
⁵Department of Physics, Arizona State University, Tempe, Arizona 85287, USA