Journal of East China Normal University(Natural Sc ›› 2017, Vol. 2017 ›› Issue (2): 97-106.doi: 10.3969/j.issn.1000-5641.2017.02.013

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A negatively charged VSiON center for implementation as qubit

SHEN Yu-hao1, TANG Zheng1, PENG Wei2   

  1. 1. Key Laboratory of Polar Materials and Devices, East China Normal University, Shanghai 200241, China;
    2. Information Technology Services Center, East China Normal University, Shanghai 200062, China
  • Received:2016-03-16 Online:2017-03-25 Published:2017-03-23

Abstract:

γ-Si3N4 is a nitrogen-based ultra-hard ceramic with Si atoms occupying both tetrahedral and octahedral sites in a spinel structure. Based on first-principles calculations, we investigate spin-polarized electronic structures and energetic stabilities of oxygenvacancy complex center (VSiON) consisting of a substituted oxygen atom and an adjacent tetrahedrally coordinated silicon vacancy in spinel silicon nitride (γ-Si3N4) with different charge states. We find that the negatively charged VSiON-1 center is stable in the p-type γ-Si3N4 and the defect center possesses an S=1 triplet ground state and a spin-conserved excited state with low excitation energy. By using a mean-field approximation, we estimate that the spin coherence time of VSiON is 0.4 s at T=0 K, which indicates that the VSiON-1 center is a promising candidate for spin coherent manipulation and qubit operation.

Key words: first-principles calculations, spin-polarized electronic structures, spin coherent time, qubit operation of color centers

CLC Number: