Electron–electron double resonance detected NMR spectroscopy using ensemble NV centers at 230 GHz and 8.3 T

The nitrogen-vacancy (NV) center has enabled widespread study of nanoscale nuclear magnetic resonance (NMR) spectroscopy at low fields. NMR high fields significantly improves the technique's spectral resolution, enabling clear identification closely related chemical species. However, NV-detected is typically performed using AC sensing through electron spin echo envelope modulation (ESEEM), a hyperfine spectroscopic technique that not feasible Within this paper, we have explored an for applications field NMR. We demonstrated optically detected (ODMR) with NV Larmor frequency 230 GHz 8.3 Tesla, corresponding to proton 350 MHz. also first measurement electron-electron double (EDNMR) and successfully $^{13}C$ bath spins. described limited by longitudinal relaxation time ($T_1$), transverse ($T_2$). Future method perform external spins T even higher are discussed.