Phys.org  July 25, 2024 The detection of faint magnetic fields from single-electron and nuclear spins at the atomic scale is a long-standing challenge in physics. While current mobile quantum sensors achieve single-electron spin sensitivity, atomic spatial resolution remains elusive for existing techniques. An international team of researchers (Germany, South Korea) fabricated a single-molecule quantum sensor at the apex of the metallic tip of a scanning tunnelling microscope by attaching Fe atoms and a PTCDA (3,4,9,10-perylenetetracarboxylic-dianhydride) molecule to the tip apex. They addressed the molecular spin by electron spin resonance and achieved ~100 neV resolution in energy. In a proof-of-principle experiment, they […]