Magnetic resonance in defect spins mediated by spin waves

Abstract

In search of two level quantum systems that implement a qubit, the nitrogen-vacancy (NV) center in diamond has been intensively studied for years. Despite favorable properties such as remarkable defect spin coherence times, the addressability of NV centers raises some technical issues. The coupling of a single NV center to an external driving field is limited to short distances, since an efficient coupling requires the NV to be separated by only a few microns away from the source. As a way to overcome this problem, an enhancement of coherent coupling between NV centers and a microwave field has recently been experimentally demonstrated using spin waves propagating in an adjacent yttrium iron garnet (YIG) film 1 . In this paper we analyze the optically detected magnetic resonance spectra that arise when an NV center is placed on top of a YIG film for a geometry similar to the one in the experiment. We analytically calculate the oscillating magnetic field of the spin wave on top of the YIG surface to determine the coupling of spin waves to the NV center. We compare this coupling to the case when the spin waves are absent and the NV center is driven only with the antenna field and show that the calculated coupling enhancement is dramatic and agrees well with the one obtained in the recent experiment.

Electrical control of coherent spin rotation of a single-spin qubit

“…At the off-resonant condition, /√ follows an average value of 120 MHz/√mW. The enhancement ratio of /√ reaches 129, 138, 48, and 17 at the resonant condition of k1, k2, k3, and k4 spin wave modes, respectively, in quantitative agreement with the analytical theoretical calculations 35 (see supplementary note 2). We notice that the enhancement of /√ decreases with the increase of the wavevector, which is attributable to a reduced microwave excitation efficiency of the higher order propagating spin wave modes.…”

Quantum Engineering With Hybrid Magnonic Systems and Materials (Invited Paper)

“…10(e)], it was demonstrated that directly driving these spin waves could coherently drive NV centers over a distance of several hundred microns up to several millimeters,. 209,210,251 In particular, it was found that reducing the microwave power reduced noise from off-resonant spin wave excitations and revealed a considerable enhancement of the local microwave driving field mediated by spin waves compared to the driving field directly coupled to the antenna. As observed in Fig.…”

Probing Thermal Magnon Current Mediated by Coherent Magnon via Nitrogen-Vacancy Centers in Diamond

“…2c, a discretized and broadened resonance line owing to the frequency matching between the NV spins and the different MSSW modes (Fig. 2d) was observed 17,34 (Fig. 2e).…”