Long-distance excitation of nitrogen-vacancy centers in diamond via\n surface spin waves

Abstract

Coherent communication over mesoscale distances is a necessary condition for\nthe application of solid-state spin qubits to scalable quantum information\nprocessing. Among other routes under study, one possibility entails the\ngeneration of magnetostatic surface spin waves (MSSW) dipolarly coupled to\nshallow paramagnetic defects in wide-bandgap semiconductors. As an initial step\nin this direction, here we make use of room-temperature MSSWs to mediate the\ninteraction between the microwave field from an antenna and the spin of a\nnitrogen-vacancy (NV) center in diamond. We show that this transport spans\ndistances exceeding 3 mm, a manifestation of the MSSW robustness and long\ndiffusion length. Using the NV spin as a local sensor, we find that the MSSW\namplitude grows linearly with the applied microwave power, suggesting this\napproach could be extended to amplify the signal from neighboring spin qubits\nby several orders of magnitude.\n