Isotopic control of the boron-vacancy spin defect in hexagonal boron nitride

Authors :: Clua-Provost, T.
Durand, A.
Mu, Z.
Rastoin, T.
Fraunié, J.
Janzen, E.
Schutte, H.
Edgar, J. H.
Seine, G.
Claverie, A.
Marie, X.
Robert, C.
Gil, B.
Cassabois, G.
Jacques, V.
Source :: Phys. Rev. Lett. 131, 126901 (2023)
Publication Year :: 2023
Abstract: We report on electron spin resonance (ESR) spectroscopy of boron-vacancy (V$_\text{B}^-$) centers hosted in isotopically-engineered hexagonal boron nitride (hBN) crystals. We first show that isotopic purification of hBN with $^{15}$N yields a simplified and well-resolved hyperfine structure of V$_\text{B}^-$ centers, while purification with $^{10}$B leads to narrower ESR linewidths. These results establish isotopically-purified h$^{10}$B$^{15}$N crystals as the optimal host material for future use of V$_\text{B}^-$ spin defects in quantum technologies. Capitalizing on these findings, we then demonstrate optically-induced polarization of $^{15}$N nuclei in h$^{10}$B$^{15}$N, whose mechanism relies on electron-nuclear spin mixing in the V$_\text{B}^-$ ground state. This work opens up new prospects for future developments of spin-based quantum sensors and simulators on a two-dimensional material platform.<br />Comment: 6 pages, 3 figure