Quantum sensing and metrology encompasses a class of techniques and devices that exploit quantum properties such as coherent superposition, wave-particle duality, and entanglement to detect weak or nanoscale signals arising, e.g., from electromagnetic fields, temperature, gravitational gradients, and pressure. As their behavior is tied to physical constants and symmetries, quantum sensors can achieve accuracy, repeatability, and precision approaching fundamental limits. As a result, these devices have shown utility in a wide range of applications spanning across the physical and life sciences —leading to a new generation of real-world technologies with exciting potential. Example quantum sensing platforms to be discussed include atom interferometers; optically-active quantum defects in solids, which have electronic and nuclear spin and can be deployed both for nanoscale sensing with single defects and for bulk sensing with dense ensembles of defects; and atomic vapors constrained in micro-machined (“chip-scale”) chambers. Applications being pursued include searches for dark matter; mid-frequency detectors of gravitational waves; probing of novel 2D materials; biomedical diagnostics; NMR of single cells and molecules; neuroscience; and vehicle navigation in the absence of GPS signals. The tutorial will provide an introduction to the principles, techniques, and operating regimes of different quantum sensing modalities, emerging areas of application, and key open questions in the field.
- Ron Walsworth