Perspective: nanoscale electric sensing and imaging based on quantum sensors

There is a rich of electric phenomena ubiquitously existing in novel quantum materials and advanced electronic devices. Microscopic understanding of the underlying physics relies on the sensitive and quantitative measurements of the electric field, electric current, electric potential, and other related physical quantities with a spatial resolution down to nanometers. Combined with a scanning probe microscope (SPM), the emergent quantum sensors of atomic/nanometer size provide promising platforms for imaging various electric parameters with a sensitivity beyond a single electron/charge. In this perspective, we introduce the working principle of such newly developed technologies, which are based on the strong sensitivity of quantum systems to external disturbances. Then we review the recent applications of those quantum sensors in nanoscale electric sensing and imaging, including a discussion of their privileges over conventional SPM techniques. Finally, we propose some promising directions for the future developments and optimizations of quantum sensors in nanoscale electric sensing and imaging.