Isotope engineering for spin defects in van der Waals materials

Ruotian Gong; Xinyi Du; Eli Janzen; Vincent Liu; Zhongyuan Liu; Guanghui He; Bingtian Ye; Tongcang Li; Norman Y Yao; James H Edgar; Erik A Henriksen; Chong Zu

doi:10.1038/s41467-023-44494-3

Isotope engineering for spin defects in van der Waals materials

Nat Commun. 2024 Jan 2;15(1):104. doi: 10.1038/s41467-023-44494-3.

Authors

Ruotian Gong^#¹, Xinyi Du^#¹, Eli Janzen², Vincent Liu³, Zhongyuan Liu¹, Guanghui He¹, Bingtian Ye³, Tongcang Li^{4

5}, Norman Y Yao³, James H Edgar², Erik A Henriksen^{1

6}, Chong Zu^{7

8}

Affiliations

¹ Department of Physics, Washington University, St. Louis, MO, 63130, USA.
² Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, KS, 66506, USA.
³ Department of Physics, Harvard University, Cambridge, MA, 02138, USA.
⁴ Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA.
⁵ Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, 47907, USA.
⁶ Institute of Materials Science and Engineering, Washington University, St. Louis, MO, 63130, USA.
⁷ Department of Physics, Washington University, St. Louis, MO, 63130, USA. zu@wustl.edu.
⁸ Institute of Materials Science and Engineering, Washington University, St. Louis, MO, 63130, USA. zu@wustl.edu.

^# Contributed equally.

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 h¹⁰B¹⁵N 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 T₂ and relaxation time T₁. For quantum sensing, [Formula: see text] centers in our h¹⁰B¹⁵N 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 ¹⁵N 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.