Toroidal Fermi-surface geometry and phonon-limited transport in nodal-line semimetals

TL;DR

This paper investigates how the unique toroidal Fermi surface geometry in doped nodal-line semimetals influences phonon-limited charge transport, revealing distinct temperature regimes and transport behaviors.

Contribution

It introduces a minimal model analyzing electron-phonon scattering in NLSs, highlighting the impact of toroidal Fermi surface geometry on transport properties and Bloch-Grüneisen temperatures.

Findings

Identification of two distinct Bloch-Grüneisen temperatures

Discovery of an intermediate temperature regime with specific decay rate and conductivity scaling

Asymptotic behaviors of decay rate and conductivity at low and high temperatures

Abstract

Nodal-line semimetals (NLSs) can display unconventional quasiparticle dynamics and charge transport properties due to their extended band degeneracy and the peculiar geometry of their Fermi surface. We consider electron-acoustic phonon scattering as the dominant relaxation mechanism and compute the quasiparticle decay rate and dc conductivity by solving the linearized semiclassical Boltzmann equation in a minimal model of a doped circular NLS. We find that the toroidal geometry of the Fermi surface gives rise to two parametrically distinct Bloch-Gr\"uneisen temperatures, associated with momentum transfers along the poloidal and toroidal directions, respectively. As a result, an intermediate temperature window opens between these two scales, in which the decay rate follows $\Gamma\propto T^2$, while the conductivity follows $\sigma\propto T^{-2}$. We also obtain the low- and high-temperature asymptotic behaviors, and discuss implications for ARPES and transport measurements in candidate NLS materials.