Interacting nodal semimetals with nonlinear bands

Abstract

We investigate the quasiparticle and transport properties of a model describing interacting Dirac and Weyl semimetals in the presence of local Hubbard repulsion U, where we explicitly include a deviation from the linearity of the energy-momentum dispersion through an intermediate-energy scale Λ. Our focus lies on the correlated phase of the semimetal. At the nodal point, the renormalization of spectral weight at a fixed temperature T exhibits a weak dependence on Λ but is sensitive to the proximity to the Mott transition. Conversely, the scattering rate of quasiparticles and the resistivity display high-temperature exponents that crucially rely on Λ, leading to a crossover towards a conventional Fermi-liquid behavior at finite T. Finally, by employing the Nernst-Einstein relation for conductivity, we identify a corresponding density crossover as a function of the chemical potential.