Local Optical Spectroscopy in Quantum Confined Systems: A Theoretical Description

TL;DR

This paper presents a theoretical framework for local optical spectroscopy in quantum confined systems, emphasizing the role of excitonic effects in spectral variations at nanometer scales.

Contribution

It introduces a density-matrix based theoretical model for local absorption, accounting for Coulomb correlation, applied to coupled quantum wires.

Findings

Excitonic effects significantly influence local absorption spectra.

The model impacts the interpretation of near-field optical measurements.

Spectral variations depend on quantum state extensions.

Abstract

A theoretical description of local absorption is proposed in order to investigate spectral variations on a length scale comparable with the extension of the relevant quantum states. A general formulation is derived within the density-matrix formalism including Coulomb correlation, and applied to the prototypical case of coupled quantum wires. The results show that excitonic effects may have a crucial impact on the local absorption with implications for the spatial resolution and the interpretation of near-field optical spectra.