Symmetric carbon tetramers forming chemically stable spin qubits in hBN

Abstract

Point defect quantum bits in semiconductors have the potential to revolutionize sensing at atomic scales. Currently, vacancy related defects, such as the NV center in diamond and the VB${}^{-}$ in hexagonal boron nitride (hBN), are at the forefront of high spatial resolution and low dimensional sensing. On the other hand, vacancies' reactive nature and instability at the surface limit further developments. Here, we study the symmetric carbon tetramers in hBN and propose them as a chemically stable spin qubit for sensing in low dimensions. We utilize periodic-DFT and quantum chemistry approaches to reliably and accurately predict the electronic, optical, and spin properties of the studied defect. We show that the nitrogen centered symmetric carbon tetramer gives rise to spin state dependent optical signals with strain sensitive intersystem crossing rates. Furthermore, the weak hyperfine coupling of the defect to their spin environments results in a reduced electron spin resonance linewidth that may enhance sensitivity.

main document (29 pages, 5 figures, 2 tables) + supplementary material (14 pages, 9 figures, 7 tables)

References in corpus (8)

• High-sensitivity diamond magnetometer with nanoscale resolution
• Coherent control of single spins in silicon carbide at room temperature
• Van der Waals heterostructures for high-performance device applications: challenges and opportunities
• High-contrast plasmonic-enhanced shallow spin defects in hexagonal boron nitride for quantum sensing
• \emph{Ab initio} calculation of spin-orbit coupling for NV center in diamond exhibiting dynamic Jahn-Teller effect
• Isolating hydrogen in hexagonal boron nitride bubbles by a plasma treatment
• Electron-nuclear coherent coupling and nuclear spin readout through optically polarized VB- spin states in hBN
• A quantum coherent spin in a two-dimensional material at room temperature

Cited by in corpus (6)

• The hBN defects database: a theoretical compilation of color centers in hexagonal boron nitride
• First principles theory of the nitrogen interstitial in hBN: a plausible model for the blue emitter
• Advancing the hBN Defects Database through Photophysical Characterization of Bulk hBN
• First-principles computational methods for quantum defects in two-dimensional materials: A perspective
• A charge transfer mechanism for optically addressable solid-state spin pairs
• CBVB-nH complexes as prevalent defects in metal-organic vapor-phase epitaxy-grown hexagonal boron nitride