Self-consistent far-infrared response of quantum-dot structures

Abstract

We develop a first-principles, self-consistent theory of the far-infrared (FIR) electromagnetic response for electrons confined in a quantum dot. We find that for small electron number ${\mathit{n}}_{\mathit{e}}$, the FIR absorption spectrum corresponds to that associated with parabolic confinement, i.e., absorption dominated by a single peak, which occurs at the frqeuency corresponding to the interlevel separation of the parabolic potential, and is roughly independent of ${\mathit{n}}_{\mathit{e}}$. For large electron number, an upward shift in the resonance frequency occurs as the electron density probes the increasingly nonparabolic curvature of the dot potential. Effects of an applied magnetic field are also investigated.