Keithly Award: Challenges and opportunities for sensing with quantum states in semiconductors*

Quantum states in semiconductors based on dopants and defects have attracted significant interest as potential atomic-scale sensors with a wide range of applications. The electron spin associated with these localized states exhibits long-lived coherence persisting up to room temperature and has been utilized to precisely measure local strain, temperature, magnetic and electric fields [1]. Using scanning probe tips with embedded single spins to high-sensitivity spin ensemble sensors in bulk and nanoscale materials, the field is rapidly expanding into diverse areas including sensing in-vivo and in high pressure environments. We discuss these recent advances involving new defects and host materials, nanoparticle synthesis, optimization and advanced measurement techniques for sensing electric, magnetic, thermal fields and strain. We highlight the opportunities for sensing using these long-lived spin states with the mapping of photocurrents in 2D materials, alongside demonstrations of all-optical sensing and nanoscale NMR. As quantum sensing and imaging continue to mature, their remarkable combination of spatial resolution, versatility, and sensitivity may open new avenues of investigation across a wide range of disciplines.

[1] Gary Wolfowicz, F. Joseph Heremans, Christopher P. Anderson, Shun Kanai, Hosung Seo, Adam
Gali, Giulia Galli, David D. Awschalom, "Qubit guidelines for solid-state spin defects," arXiv:2010.16395.