Faraday Rotation Spectroscopy of Quantum-Dot Quantum Wells

TL;DR

This paper models Faraday rotation in quantum-dot quantum wells, revealing that symmetry breaking explains experimental resonance features better than perfect spherical models.

Contribution

It introduces a theoretical calculation of Faraday rotation using k.p theory and demonstrates the importance of symmetry breaking for accurate spectral predictions.

Findings

Perfect spherical symmetry does not reproduce experimental resonances.

Broken symmetry models align better with observed spectra.

Theoretical calculations match key experimental features.

Abstract

Time-resolved Faraday rotation studies of CdS/CdSe/CdS quantum-dot quantum wells have recently shown that the Faraday rotation angle exhibits several well-defined resonances as a function of probe energy close to the absorption edge. Here, we calculate the Faraday rotation angle from the eigenstates of the quantum-dot quantum well obtained with k.p theory. We show that the large number of narrow resonances with comparable spectral weight observed in experiment is not reproduced by the level scheme of a quantum-dot quantum well with perfect spherical symmetry. A simple model for broken spherical symmetry yields results in better qualitative agreement with experiment.