21st Century Quantum Sensing — Raphael C Pooser | Duke FIP

2022 Fitzpatrick Institute Symposium at Duke University:
Quantum sensors are devices that exploit quantum mechanical effects to obtain enhanced sensitivity over their classical counterparts. Sensors that exploit quantum noise reduction, or squeezed light, have seen renewed interest in
recent years as a growing number of devices that utilize optical readout – from gravitational wave detection to ultratrace plasmonic sensing at the nanoscale – have approached their absolute limits of detection as defined by the Heisenberg uncertainty principle. At this limit, the noise is dominated by the quantum statistics of light (the shot noise limit when coherent light is used) and the quantum back action. Simultaneously, many devices, including nanoscale sensors, have reached tolerance thresholds in which power in the readout field can no longer be increased. Beyond these limits, squeezed light is required to further improve sensitivity in these platforms when they are operating at the shot noise limit. Here, we present our work geared towards producing practical, ubiquitous quantum sensors that break through the shot noise limit to achieve state of the art sensitivities beyond the capabilities of classical devices. We demonstrate atomic magnetometers, quantum plasmonic imaging, quantum atomic force microscopes, and ultra-trace quantum plasmonic sensors with state-of-the-art quantum noise levels well below the shot noise limit. Further, we will outline recent innovations in interferometry which increase the dynamic range in these devices beyond what classical interferometers are capable of.