Super-resolution localization and readout of individual solid-state qubits

Abstract

A central goal in quantum information science is to establish entanglement across multiple quantum memories in a manner that allows individual control and readout of each constituent qubit. In the area of solid state quantum optics, a leading system is the negatively charged nitrogen vacancy center in diamond, which allows access to a spin center that can be entangled to multiple nuclear spins. Scaling these systems will require the entanglement of multiple NV centers, together with their nuclear spins, in a manner that allows for individual control and readout. Here we demonstrate a technique that allows us to prepare and measure individual centers within an ensemble, well below the diffraction limit. The technique relies on optical addressing of spin-dependent transitions, and makes use of the built-in inhomogeneous distribution of emitters resulting from strain splitting to measure individual spins in a manner that is non-destructive to the quantum state of other nearby centers. We demonstrate the ability to resolve individual NV centers with subnanometer spatial resolution. Furthermore, we demonstrate crosstalk-free individual readout of spin populations within a diffraction limited spot by performing resonant readout of one NV during a spectroscopic sequence of another. This method opens the door to multi-qubit coupled spin systems in solids, with individual spin manipulation and readout.