A nanometer-scale optical electrometer

Understand

Self-assembled semiconductor quantum dots show remarkable optical and spin coherence properties, which have lead to a concerted research effort examining their potential as a quantum bit for quantum information science1-6.

• Here, we present an alternative application for such devices, exploiting recent achievements of charge occupation control and the spectral tunability of the optical emission of quantum dots by electric fields7 to demonstrate high-sensitivity electric field measurement.
• In contrast to existing nanometer-scale electric field sensors, such as single electron transistors8-11 and mechanical resonators12,13, our approach relies on homodyning light resonantly Rayleigh scattered from a quantum dot transition with the excitation laser and phase sensitive lock-in detection.
• This offers both static and transient field detection ability with high bandwidth operation and near unity quantum efficiency.