Isotope engineering for spin defects in van der Waals materials.

Gong, Ruotian; Du, Xinyi; Janzen, Eli; Liu, Vincent; Liu, Zhongyuan; He, Guanghui; Ye, Bingtian; Li, Tongcang et al. · Nat Commun · 2024

basic_science · Level V

Where this comes from

Abstract

Spin defects in van der Waals materials offer a promising platform for advancing quantum technologies. Here, we propose and demonstrate a powerful technique based on isotope engineering of host materials to significantly enhance the coherence properties of embedded spin defects. Focusing on the recently-discovered negatively charged boron vacancy center ([Formula: see text]) in hexagonal boron nitride (hBN), we grow isotopically purified h<sup>10</sup>B<sup>15</sup>N crystals. Compared to [Formula: see text] in hBN with the natural distribution of isotopes, we observe substantially narrower and less crowded [Formula: see text] spin transitions as well as extended coherence time T<sub>2</sub> and relaxation time T<sub>1</sub>. For quantum sensing, [Formula: see text] centers in our h<sup>10</sup>B<sup>15</sup>N samples exhibit a factor of 4 (2) enhancement in DC (AC) magnetic field sensitivity. For additional quantum resources, the individual addressability of the [Formula: see text] hyperfine levels enables the dynamical polarization and coherent control of the three nearest-neighbor <sup>15</sup>N nuclear spins. Our results demonstrate the power of isotope engineering for enhancing the properties of quantum spin defects in hBN, and can be readily extended to improving spin qubits in a broad family of van der Waals materials.