Abstract:

Nitrogen-Vacancy (NV) color centers in diamond provide an atomic-like quantum system embedded in a solid-state structure. As such, they offer a bridge between the fields of atomic physics and condensed matter physics, with emerging applications ranging from quantum information processing and magnetic field sensing to quantum many-body spin bath dynamics.
In this talk I will first describe our work on applying dynamical decoupling approaches to extend the limit of the coherence time of the NV spin qubit, and its effect on the NV sensitivity as a magnetic field sensor. In both cases we achieve an order-of-magnitude improvement at room temperature, and at least 2 orders-of-magnitude improvement at low temperatures.
Secondly, we utilize the dynamical decoupling sequences mentioned above to realize a coherent spectroscopic technique, in which the NV is used as a probe of the dynamics of its composite solid-state spin environment. We identify a possible new mechanism in diamond for suppression of electronic spin bath dynamics in the presence of a nuclear spin bath of sufficient concentration. This suppression enhances the efficacy of dynamical decoupling techniques, resulting in increased coherence times for multi-spin-qubit systems, thus paving the way for applications in quantum information, sensing and metrology.
Finally, we directly drive the bath spins to enhance their coupling to the NV spin, and observe the transfer of polarization from the NV to the bath. These results pave the way for cooling of the spin bath and for measurements of quantum dynamics of this many-body spin system.