Dynamic nuclear polarization weighted spectroscopy of multispin electronic-nuclear clusters

PIGLIAPOCHI, ROBERTA; PAGLIERO, DANIELA; BULJUBASICH, LISANDRO; LOZOVOI, ARTUR; ACOSTA, RODOLFO H.; ZANGARA, PABLO R.; MERILES, CARLOS A.

Physical Review B

Elsevier

Año: 2023 vol. 107

2469-9950

Nuclear spins and paramagnetic centers in a solid randomly group to form clusters featuring nearly-degenerate, hybridstates whose dynamics are central to processes involving nuclear spin-lattice relaxation and diffusion. Theircharacterization, however, has proven notoriously difficult mostly due to their relative isolation and comparatively lowconcentration. Here, we combine field-cycling experiments, optical spin pumping, and variable radiofrequency (RF)excitation to probe transitions between hybrid multi-spin states formed by strongly coupled electronic and nuclear spins indiamond. Leveraging bulk nuclei as a collective time-integrating sensor, we probe the response of these spin clusters as wesimultaneously vary the applied magnetic field and RF excitation to reconstruct multi-dimensional spectra. We uncovercomplex nuclear polarization patterns of alternating sign that we qualitatively capture through analytical and numericalmodeling. Our results unambiguously expose the impact that strongly-hyperfine-coupled nuclei can have on the spindynamics of the crystal, and inform future routes to spin cluster control and detection.