Nanoscale control and readout of nitrogen vacancy ensembles for imaging and many-body physics

Ensembles of nitrogen vacancy (NV) centers in diamond enable a wide range of room-temperature quantum experiments, from nanoscale magnetic imaging to the realization of discrete time-crystalline order. However the nanoscale spacing of NV defects typically restricts control and readout to global observables, which limits the range of observable many-body effects and the spatial resolution of ensemble-based sensing. In this work, we develop an experimental platform hosting strong magnetic field gradients with fast dynamical control. The system consists of four on-chip microcoils which can generate an arbitrary in-plane linear gradient. Nanosecond electrical control enables the application of fast gradient pulses, which can be synchronized with spin echo and decoupling pulses. We demonstrate greater than 0.2 G/nm field strengths, which are sufficient to wind spin-helices with a spatial wavelength smaller than the typical NV-NV spacing. We discuss the outlook for three primary applications: the study of spin transport via preparation of inhomogeneous spin-helix states, nanoscale Fourier magnetic imaging, and a novel protocol to implement spin-squeezing dynamics in 3D dipolar ensembles of NV centers.