Interband response in spin-orbit coupled topological semimetals

TL;DR

This paper explores how spin-orbit coupling and disorder influence interband conductivity in nodal line semimetals, revealing anisotropic responses and tunable peaks with potential experimental implications.

Contribution

It introduces a quantum kinetic analysis of disorder and field-driven interband conductivity in spin-orbit coupled NLSMs, highlighting anisotropic effects and tunable transition peaks.

Findings

Disorder reshapes interband response anisotropically.

A tunable transition peak arises from non-Pauli-blocked states.

Numerical estimates for TaAs suggest experimental relevance.

Abstract

This study investigates the interband conductivity for nodal line semimetals (NLSMs) in the presence of spin-orbit coupling (SOC) beyond the clean limit, where the disorder reshapes the transport properties. The SOC breaks spin degeneracy, thus fundamentally altering the band dispersion and enabling multiple interband transport channels. Using a quantum kinetic framework, we analyze the interband conductivity originating from disorder-driven (extrinsic) and field-driven (intrinsic) mechanisms. We find that the interband response shows an anisotropic nature due to disorder driven counter parts. Additionally, our predictions show a tunable prominent transition peak arising from non-Pauli-blocked states that can be controlled via band parameters as well as external stimuli. To have an experimental relevance, we provide a numerical estimation for the interband response of TaAs using density functional theory estimated parameters. These results suggest the investigation of disorder-enabled signatures in spin systems.