Single-Atom Spin Resonance in a Scanning Tunneling Microscope
Recently, the ability to drive electron spin resonance (ESR) of individual atoms using a scanning tunneling microscope (STM) provided a major step forward in sensing and manipulating magnetism at the atomic scale. The atomic-scale spatial resolution and the ultrahigh energy resolution of ESR-STM has allowed the measurement of the magnetic dipolar interaction between two atoms placed a few nanometers apart on a surface, the detection of hyperfine interaction between electronic and nuclear spins of individual atoms, as well as the exploration of quantum fluctuations in designed spin arrays having tailored geometries. By implementing pulsed ESR, coherent spin manipulation of magnetic atoms and engineered atomic dimers on surfaces have been achieved by demonstrating Rabi oscillations, Ramsey fringes and spin echoes, opening the door to a powerful suite of pulsed techniques that can extend single-atom sensing capabilities. Coherent control of spins arranged with atomic precision provides a solid-state platform for quantum simulation of many-body systems.