Cavity-enhanced charge-driven feedback loop in single quantum dot photocurrent spectroscopy

This study investigates a charge-driven feedback loop on single quantum dots (QDs) embedded in micropillar cavities under electrical readout. The coupled quantum–dot–microcavity system demonstrates a significant reduction in hysteresis under temperature sweep when the QD is in resonance with the cavity mode. To describe the experimental results, we develop a feedback model for the photocurrent response which incorporates a quadratic Stark shift to accurately fit the observed asymmetries and hysteresis in the spectra. Supported by this model, we attribute the observed reduction in hysteresis to an interplay between cavity-enhanced effective excitation power and the competition between radiative and nonradiative recombination by cavity quantum electrodynamics effects in the Purcell regime. This work provides important insights that can guide future optimization of QD-based devices for applications in quantum technologies.