Effects of Spin-Orbit Coupling and Thermal Expansion on the Phonon-limited Resistivity of Pb from First Principles

TL;DR

This study uses first-principles calculations to analyze how spin-orbit coupling and thermal expansion influence the phonon-limited electrical resistivity of lead, revealing their combined effects on phonon dispersion and resistivity behavior at high temperatures.

Contribution

It provides a detailed ab initio analysis of the impact of spin-orbit coupling and thermal expansion on Pb's resistivity, highlighting the importance of these factors in theoretical modeling.

Findings

SOC improves phonon dispersion and resistivity description

Thermal expansion introduces non-linearity in resistivity at high temperatures

Including mechanisms beyond quasi-harmonic approximation is necessary for accurate modeling

Abstract

Using density functional theory calculations with spin-orbit coupling (SOC), we report on the temperature-dependent thermodynamical properties of Pb: electrical resistivity, thermal expansion (TE), heat capacity, bulk modulus and its pressure derivative. For the former, we employed the state-of-the-art ab initio Boltzmann Transport Equation formalism, and we calculated the effect of TE. In accordance with previous work, we show that SOC improves the description of the phonon dispersion and the resistivity. We argue that this is caused by a joint mutual effect of an increase in the electronic nesting and an increase in the electron-phonon coupling. Interestingly, including TE incorporates non-linearity into the resistivity at high temperatures, whose magnitude depends on whether SOC is included or not. We suggest that mechanisms beyond the quasi-harmonic approximation should be considered to get a better description of Pb with SOC at high temperatures.