Point defect quantum bits in semiconductors have the potential to revolutionize sensing at atomic scales.Currently,vacancy-related defects are at the forefront of high spatial resolution and low-dimensional sensing.On...Point defect quantum bits in semiconductors have the potential to revolutionize sensing at atomic scales.Currently,vacancy-related defects are at the forefront of high spatial resolution and low-dimensional sensing.On the other hand,it is expected that impurity-related defect structures may give rise to new features that could further advance quantum sensing in low dimensions.Here,we study the symmetric carbon tetramer clusters in hexagonal boron nitride and propose them as spin qubits for sensing.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 can enhance sensitivity.展开更多
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 rece...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.展开更多
文摘Point defect quantum bits in semiconductors have the potential to revolutionize sensing at atomic scales.Currently,vacancy-related defects are at the forefront of high spatial resolution and low-dimensional sensing.On the other hand,it is expected that impurity-related defect structures may give rise to new features that could further advance quantum sensing in low dimensions.Here,we study the symmetric carbon tetramer clusters in hexagonal boron nitride and propose them as spin qubits for sensing.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 can enhance sensitivity.
基金This work was financially supported by the Knut and Alice Wallenberg Foundation through WBSQD2 project(Grant No.2018.0071)G.B.is supported by NKFIH PD-17-125261+4 种基金“Bolyai”Research Scholarship of HAS.Ö.L.acknowledges grant NKFIH K120569the support of the Alexander von Humboldt FoundationA.G.acknowledges the Hungarian NKFIH grants No.KKP129866 of the National Excellence Program of Quantum-coherent materials projectÖ.L.and A.G.acknowledge support of the NKFIH through the National Quantum Technology Program(Grant No.2017-1.2.1-NKP-2017-00001)The calculations were performed on resources provided by the Swedish National Infrastructure for Computing(SNIC 2018/3-625 and SNIC 2019/1-11)at the National Supercomputer Center(NSC)and by the Wigner RCP.
文摘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.