Time-resolved vacuum Rabi oscillations in a quantum dot-nanocavity system

TL;DR

This paper demonstrates the time-resolved observation of vacuum Rabi oscillations in a quantum dot-nanocavity system, revealing how pump parameters influence quantum dot dynamics and suggesting a new method for probing cavity QED phenomena.

Contribution

It presents the first time-domain measurement of vacuum Rabi oscillations in a quantum dot-nanocavity system with high-Q photonic crystal cavities, highlighting their sensitivity to quantum dot dynamics.

Findings

Vacuum Rabi oscillations were observed in the time domain using photoluminescence.

Modifications in oscillations depend on pump wavelength and intensity.

Oscillation behavior is influenced by carrier capture and dephasing dynamics.

Abstract

We report time-domain observation of vacuum Rabi oscillations in a single quantum dot strongly coupled to a nanocavity under incoherent optical carrier injection. We realize a photonic crystal nanocavity with a very high quality factor of >80,000 and employ it to clearly resolve the ultrafast vacuum Rabi oscillations by simple photoluminescence-based experiments. We found that the time-domain vacuum Rabi oscillations were largely modified when changing the pump wavelength and intensity, even when marginal changes were detected in the corresponding photoluminescence spectra. We analyze the measured time-domain oscillations by fitting to simulation curves obtained with a cavity quantum electrodynamics model. The observed modifications of the oscillation curves were mainly induced by the change in the carrier capture and dephasing dynamics in the quantum dot, as well as the change in bare-cavity emission. This result suggests that vacuum Rabi oscillations can be utilized as a highly sensitive probe for the quantum dot dynamics. Our work points out a powerful alternative to conventional spectral-domain measurements for a deeper understanding of the vacuum Rabi dynamics in quantum dot-based cavity quantum electrodynamics systems.