Spin Ensembles in Diamond for Sensing and Many-Body Physics
The study of quantum many-body spin physics in realistic solid-state platforms has been a long-standing goal in quantum and condensed-matter physics. We demonstrate separate steps required to reach this goal using NV centers in diamond. First, standard (TEM) electron irradiation is used for the enhancement of N to NV conversion efficiencies by over an order-of-magnitude . Second, robust pulsed  and continuous  dynamical decoupling (DD) techniques enable the preservation of arbitrary states of the ensemble. These combined efforts, which already resulted in the demonstration of enhanced magnetic sensing , could lead to the desired interaction-dominated regime. Finally, we simulate the effects of continuous and pulsed microwave (MW) control on the resulting NV-NV many body dynamics in a realistic spin-bath environment . We emphasize that dominant interaction sources could be identified and decoupled by the application of proper pulse sequences, and the modification of such sequences could lead to the creation engineered interaction Hamiltonians. Such interaction Hamiltonians could pave the way toward the creation of non-classical states, e.g. spin-squeezed states, which were not yet demonstrated in the solid-state, and could eventually lead to magnetic sensing beyond the standard quantum limit (SQL).
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