Resonance Raman scattering in semiconductor quantum dots: Adiabatic vs. time-dependent perturbation theory

TL;DR

This paper compares adiabatic and time-dependent perturbation theories for resonance Raman scattering in semiconductor quantum dots, extending the adiabatic approach with non-adiabatic corrections and evaluating their differences.

Contribution

It revises the adiabatic theory with non-adiabatic corrections and compares it to the time-dependent approach, clarifying their applicability and differences.

Findings

Both theories are equivalent under weak coupling and non-degenerate states.

The B term in the adiabatic theory can generally be neglected.

Evaluations for CdSe and CdS nanocrystals support the theoretical analysis.

Abstract

The adiabatic theory of resonance one-phonon Raman scattering in semiconductor nanocrystals is revised and extended with perturbative non-adiabatic corrections, given by the Albrecht's B term. This theory is confronted with the time-dependent perturbation approach, pointing at their differences and similarities. It is shown that both theories are equivalent in the limit of weak electron-phonon coupling and non-degenerate or uncoupled resonant states. Evaluations of the A and B terms for the confined LO phonon in CdSe and CdS nanocrystals are reported. These evaluations show that the B term can usually be neglected.