Ab initio theory of the negatively charged boron vacancy qubit in hexagonal boron nitride

Viktor Ivády,Adam Gali,Gergő Thiering,Gergely Barcza,Jyh-Pin Chou,Song Li,Hanen Hamdi,Örs Legeza

doi:10.1038/s41524-020-0305-x

Abstract

Highly correlated orbitals coupled with phonons in two-dimension are identified for paramagnetic and optically active boron vacancy in hexagonal boron nitride by first principles methods which are responsible for recently observed optically detected magnetic resonance signal. Here, we report ab initio analysis of the correlated electronic structure of this center by density matrix renormalization group and Kohn-Sham density functional theory methods. By establishing the nature of the bright and dark states as well as the position of the energy levels, we provide a complete description of the magneto-optical properties and corresponding radiative and non-radiative routes which are responsible for the optical spin polarization and spin dependent luminescence of the defect. Our findings pave the way toward advancing the identification and characterization of room temperature quantum bits in two-dimensional solids.

Highlights

Hexagonal boron nitrite is a laminar van der Waals material with advanced fabrication techniques making it suitable for studying semiconductor physics in two dimensions (2D)
While the microscopic configuration and electronic structure of these emitters are still not fully understood, it is widely accepted that these color centers can be associated with point defects and point defect complexes
Published in partnership with the Shanghai Institute of Ceramics of the Chinese Academy of Sciences altogether by ten electrons in the negative charge state that come single sheet and bulk Hexagonal boron nitrite (hBN), respectively. These values are in from the three fully occupied pz orbitals and the three half-filled dangling bonds of the first neighbor nitrogen atoms and one extra remarkable agreement with the value of D ≈ 3.5 GHz reported by recent experiments for the VB assigned color center in bulk hBN6

Summary

Introduction

Hexagonal boron nitrite (hBN) is a laminar van der Waals material with advanced fabrication techniques making it suitable for studying semiconductor physics in two dimensions (2D). The wide energy gap of hBN may host numerous defects states with internal optical transitions that give rise to color centers. Some of these centers have already shown great potential in quantum technology application[1,2,3,4,5,6,7] demonstrated previously in the bulk semiconductors, such as diamond[8,9,10,11] and silicon carbide[12,13,14,15,16]. Previous investigations have focused on the optical properties of the color centers, the spin degree of freedom has been observed only in very recent experiments[5,6,7]

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