Nanoscale quantum sensors

Electric field fluctuations at the single molecule scale

Discovered in the early stage of quantum mechanics, the Stark effect is a frequency shift of a quantum emitter embedded in a static electric field. Nowadays it represents a powerful control and tuning technique which is fundamental in any quantum technological application. However, this sensitivity to static electric fields, represents also a source of decoherence. Whenever the electric field experiences some fluctuations, it triggers a linewidth broadening in the emitter going under the name “spectral diffusion”.

Schematic representation of the experiment. The local electric field is controlled by a couple of electrodes and by a special technique called OSS (optically induced Stark shift). More details at https://arxiv.org/abs/2409.01840

Nanoscale temperature and heat conductivity

At the nanometric scale, heat results in vibrations in the environment. Single molecules embedded in molecular nanocrystals are able to couple to those, making them a precise sensor for temperature.