Precise Control of Charge States in Single Quantum Dots Using Bipolar Junction Transistors

We introduce a novel method for precise control of quantum dot (QD) charge states using a bipolar junction transistor (BJT). By adjusting the base-emitter and collector-base voltages, we can switch the QD between different charge states, offering fine-tuned control over its emission properties. The QD’s charge environment, regulated by the collector current, enables precise manipulation of its optical characteristics. Experimental results demonstrate that the charged states exhibit narrow linewidths and high single-photon purity. This transistor-based approach not only facilitates the miniaturization and integration of QD devices but also provides a powerful platform for controlling spin-photon interactions, with significant potential for applications in quantum computing and networks.