Far-field optical imaging and manipulation of individual spins with nanoscale resolution

A fundamental limit to existing optical far field techniques for measurement and manipulation of spin degrees of freedom is set by diffraction. Here, we demonstrate an efficient far-field optical technique that overcomes this limit. Our technique involves selective flipping of the orientation of individual spins, associated with Nitrogen-Vacancy centers in diamond, using a focused beam of light with intensity vanishing at a controllable location. This enables simultaneous single-spin imaging and magnetometry at the nanoscale. Furthermore, by inhibiting spin transitions away from the laser intensity null using a quantum Zeno-like effect, selective coherent rotation of individual spins is realized. This technique can be extended to sub-nanometer dimensions, thus enabling applications in diverse areas ranging from quantum information science to bioimaging.