Sensing Magnetic Fields with a Giant Quantum Wave

Microscopes make small things visible, unveiling fascinating details of nature that would otherwise be hidden. A new microscope reported by Benjamin Lev and colleagues at Stanford University, California, takes this idea to a new level [1]. The team employs a quantum gas of ultracold atoms to map static (dc) magnetic fields at a material’s surface on a microscopic scale, with record field sensitivity, and over a wide temperature range. The field sensitivity of their scanning quantum cryogenic atom microscope, or SQCRAMscope, could be used to unveil the strength and spatial distribution of microscopic currents in a variety of samples. This information would help in the characterization and understanding of unconventional superconductors, strongly correlated materials, and topological materials.