Event Details

In quantum science we often simplify our analyses by treating quantum systems as two-level qubits, and by assuming that the decoherence events of two or more unentangled qubits are uncorrelated from each other. For example, both of these assumptions are central tenets of circuit-based quantum error correction protocols. However, in experiments these assumptions regularly break down, offering both challenges and opportunities. In this talk I will present concrete experimental examples in which a detailed understanding of the multi-level nature of decoherence in a specific quantum system and measurements of shot-to-shot classical correlations in the “decoherence” of qubits can be harnessed to enable new capabilities. I will first present a detailed experimental and theoretical study of spin-state-dependent spin-phonon relaxation rates in the electronic ground state spin-triplet of the nitrogen vacancy (NV) centers in diamond, and will discuss how this understanding could potentially lead to magnetometers with enhanced sensitivity. I will then present the experimental demonstration of spatiotemporal magnetic field correlation measurements with pairs of NV centers, including the ability to distinguish between global and local noise sources, and the capability to measure signals of interest using free precession times beyond the apparent single NV coherence time in certain regimes.