Strain-tunable quantum dot embedded in a nanowire antenna

We demonstrate an elastically tunable self-assembled quantum dot in a nanowire antenna that emits single photons with resolution-limited spectral linewidths. The single-photon device is composed of a single quantum dot embedded in a top-down fabricated nanowire waveguide integrated onto a piezoelectric actuator. Nonresonant excitation leads to static (fluctuating) charges likely at the nanowire surface, causing DC Stark shifts (inhomogeneous broadening); for low excitation powers, the effects are not observed, and resolution-limited linewidths are obtained. Despite significant strain-field relaxation in the high-aspect-ratio nanowires, we achieve up to 1.2-meV tuning of a dot's transition energy. Single-photon sources with high brightness, resolution-limited linewidths, and wavelength tunability are promising for future quantum technologies.