Damping of Rabi oscillations in quantum dots due to lattice dynamics

TL;DR

This paper investigates how lattice vibrations in quantum dots cause damping of Rabi oscillations, revealing a resonant interaction that limits coherent control of charge states.

Contribution

It uncovers the resonant dynamical interaction between driven carrier dynamics and lattice phonons, explaining the damping of Rabi oscillations in quantum dots.

Findings

Resonant coupling between Rabi oscillations and phonons causes damping.

High-frequency dynamics can come into resonance with phonons.

Lattice response restricts coherent control in quantum dots.

Abstract

We show that the interaction between carriers confined in a quantum dot and the surrounding lattice under external driving of carrier dynamics has a dynamical, resonant character. The quality of Rabi oscillations in such a system depends on the relation between nonlinear spectral characteristics of the driven dynamics and the spectral density of effectively coupled lattice modes (phonon frequencies and density of states). For a large number of Rabi oscillations within a fixed time (allowed by e.g. exciton recombination) the spectrum of the dynamics extends towards high frequencies, coming into resonance with acoustical and optical phonons. Thus, this resonant lattice response strongly restricts the possibility of fully coherent control over the charge state in a quantum dot.