Abstract
We calculate the thermoelectric response coefficients of three-dimensional Dirac or Weyl semimetals as a function of magnetic field, temperature, and Fermi energy. We focus in particular on the thermoelectric Hall coefficient and the Seebeck coefficient , which are well-defined even in the dissipationless limit. We contrast the behaviors of and with those of traditional Schrödinger particle systems, such as doped semiconductors. Strikingly, we find that for Dirac materials acquires a constant, quantized value at sufficiently large magnetic field, which is independent of the magnetic field or the Fermi energy, and this leads to unprecedented growth in the thermopower and the thermoelectric figure of merit. We further show that even relatively small fields, such that (where is the cyclotron frequency and is the scattering time), are sufficient to produce a more than increase in the figure of merit.
- Received 15 February 2019
DOI:https://doi.org/10.1103/PhysRevB.99.155123
©2019 American Physical Society