Microwave spin control of a van der Waals solid-state defect ensemble

Color centers in solid-state materials serve as the foundation for qubits that can be addressed optically, and spin-photon interfaces contribute to advancements in constructing quantum networks. Extensive research has focused on these defects in diamond, silicon, and silicon carbide. However, a burgeoning interest lies in investigating similar properties in emerging and innovative platforms.

In this study, we present findings concerning a specific group of defects found in a van der Waals material, specifically boron vacancies in hexagonal boron nitride (hBN). We utilize phonon sideband emission at approximately 850 nm as an effective optical readout method to examine the spin characteristics. We conduct a comparative analysis of spin qubits in naturally occurring hBN and isotopically purified hBN (B10 and N15). Our focus involves comprehensive mapping of the spin Hamiltonian as a function of the magnetic field as well as demonstrating coherent Rabi oscillations induced by microwave drive (~1-3 GHz). Additionally, we measure coherence times under different dynamical decoupling sequences, offering valuable insights into various sources of dephasing. Enhancing coherence represents a potential avenue for constructing high-precision quantum sensors and memories.