Long-range spin wave mediated control of defect qubits in nanodiamonds

Abstract

Hybrid architectures that combine nitrogen-vacancy centers in diamond with other materials and physical systems have been proposed to enhance the nitrogen-vacancy center’s capabilities in many quantum sensing and information applications. In particular, spin waves in ferromagnetic materials are a promising candidate to implement these platforms due to their strong magnetic fields, which could be used to efficiently interact with the nitrogen-vacancy centers. Here, we develop an yttrium iron garnet-nanodiamond hybrid architecture constructed with the help of directed assembly and transfer printing techniques. Operating at ambient conditions, we demonstrate that surface confined spin waves excited in the ferromagnet can strongly amplify the interactions between a microwave source and the nitrogen-vacancy centers by enhancing the local microwave magnetic field by several orders of magnitude. Crucially, we show the existence of a regime in which coherent interactions between spin waves and nitrogen-vacancy centers dominate over incoherent mechanisms associated with the broadband magnetic field noise generated by the ferromagnet. These accomplishments enable the spin wave mediated coherent control of spin qubits over distances larger than 200 μm, and allow low power operations for future spintronic technologies.