Boltzmann-Bloch Equation Approach to the Theory of the Optical Inter- and Intraband Response in Noble Metals

TL;DR

This paper develops a microscopic Boltzmann-Bloch framework to accurately model the optical response of noble metals, capturing complex electron interactions and Fermi surface effects for improved understanding of their optical properties.

Contribution

Introduction of momentum-resolved Boltzmann-Bloch equations for noble metals, enabling detailed analysis of intra- and interband optical processes with many-body interactions.

Findings

Calculated optical response of gold in near-infrared and visible range

Revealed microscopic processes underlying phenomenological models

Explained temperature-dependent spectra with anisotropic Fermi surface model

Abstract

In this paper we introduce momentum-resolved metal Boltzmann-Bloch equations (MBBE) for the combined description of electronic intra- and interband processes in noble metals. This microscopic framework incorporates a full treatment of many-body electron-electron and electron-phonon interactions, relevant for relaxation and dephasing processes after optical excitation. For the example of gold, we calculate the linear optical response for near-infrared and visible energies. This provides insight into the interplay of microscopic processes hidden in phenomenological Drude-Lorentz models. The complex geometry of the Fermi surface is treated by an anisotropic electronic dispersion model, which is necessary to explain the temperature dependent spectrum over the whole frequency range of intra- and interband transitions.