Coherent Microwave Control of a Nuclear Spin Ensemble at Room Temperature

TL;DR

This paper demonstrates room-temperature coherent control of nuclear spin ensembles in diamond NV centers using microwave fields, enabling efficient spin exchange and potential quantum information applications.

Contribution

It introduces a method for controlling nuclear spins via microwave-driven electron-nuclear spin exchange in NV centers at room temperature, which was not previously achieved.

Findings

Achieved fast Rabi oscillations on electron-nuclear transitions

Demonstrated nuclear spin polarization and coherent population trapping

Showed potential for scalable quantum information processing

Abstract

We use nominally forbidden electron-nuclear spin transitions in nitrogen-vacancy (NV) centers in diamond to demonstrate coherent manipulation of a nuclear spin ensemble using microwave fields at room temperature. We show that employing an off-axis magnetic field with a modest amplitude($\approx$ 0.01 T) at an angle with respect to the NV natural quantization axes is enough to tilt the direction of the electronic spins, and enable efficient spin exchange with the nitrogen nuclei of the NV center. We could then demonstrate fast Rabi oscillations on electron-nuclear spin exchanging transitions, coherent population trapping and polarization of nuclear spin ensembles in the microwave regime. Coupling many electronic spins of NV centers to their intrinsic nuclei offers full scalability with respect to the number of controllable spins and provides prospects for transduction. In particular, the technique could be applied to long-lived storage of microwave photons and to the coupling of nuclear spins to mechanical oscillators in the resolved sideband regime.