Electronic Structure of Neutral Silicon-Vacancy Complex in Diamond (original) (raw)

Electronic structure of the negatively charged silicon-vacancy center in diamond

Physical Review B, 2014

The negatively-charged silicon-vacancy (SiV − ) center in diamond is a promising single photon source for quantum communications and information processing. However, the center's implementation in such quantum technologies is hindered by contention surrounding its fundamental properties. Here we present optical polarization measurements of single centers in bulk diamond that resolve this state of contention and establish that the center has a 111 aligned split-vacancy structure with D 3d symmetry. Furthermore, we identify an additional electronic level and evidence for the presence of dynamic Jahn-Teller effects in the center's 738 nm optical resonance.

Electronic Structure of the Silicon Vacancy Color Center in Diamond

Physical Review Letters, 2014

The negatively charged silicon vacancy (SiV) color center in diamond has recently proven its suitability for bright and stable single photon emission. However, its electronic structure so far has remained elusive. We here explore the electronic structure by exposing single SiV defects to a magnetic field where the Zeeman effect lifts the degeneracy of magnetic sublevels. The similar response of single centers and a SiV ensemble in a low strain reference sample proves our ability to fabricate almost perfect single SiVs, revealing the true nature of the defect's electronic properties. We model the electronic states using a group-theoretical approach yielding a good agreement with the experimental observations. Furthermore, the model correctly predicts polarization measurements on single SiV centers and explains recently discovered spin selective excitation of SiV defects. PACS numbers: 81.05.ug, 61.72.jn, 78.55.-m, 71.70.Ej

Electron–phonon processes of the silicon-vacancy centre in diamond

New Journal of Physics, 2015

We investigate phonon induced electronic dynamics in the ground and excited states of the negatively charged silicon-vacancy (SiV − ) centre in diamond. Optical transition line widths, transition wavelength and excited state lifetimes are measured for the temperature range 4 K-350 K. The ground state orbital relaxation rates are measured using time-resolved fluorescence techniques. A microscopic model of the thermal broadening in the excited and ground states of the SiV − centre is developed. A vibronic process involving single-phonon transitions is found to determine orbital relaxation rates for both the ground and the excited states at cryogenic temperatures. We discuss the implications of our findings for coherence of qubit states in the ground states and propose methods to extend coherence times of SiV − qubits.

Density functional simulations of silicon-containing point defects in diamond

Silicon impurities in diamond lead to the appearance of the well known system of 12 lines around 1.681 eV, thought to arise from the silicon-vacancy complex. This system is produced by various treatments suggestive of other silicon-related centers in the material. In order to elucidate possible structures of Si in diamond, we have performed first-principles calculations. We show that interstitial Si is unstable at growth temperatures, substitutional Si is most likely visible only by vibrational mode spectroscopy, and complexes of silicon with lattice vacancies are electrically, paramagnetically, and optically active. In addition, we report on Si-N and Si-H complexes in the context of doping and the KUL3 electron paramagnetic resonance center, respectively.

Optical signatures of silicon-vacancy spins in diamond

2014

Colour centres in diamond have emerged as versatile tools for solid-state quantum technologies ranging from quantum information [1-3] to metrology [4-7], where the nitrogen-vacancy centre is the most studied to-date. Recently, this toolbox has expanded to include different materials [8, 9] for their nanofabrication opportunities, and novel colour centres [10-16] to realize more efficient spin-photon quantum interfaces. Of these, the silicon-vacancy centre stands out with ultrabright single photon emission predominantly into the desirable zero-phonon line [14]. The challenge for utilizing this centre is to realise the hitherto elusive optical access to its electronic spin. Here, we report spin-tagged resonance fluorescence from the negatively charged silicon-

Electrical excitation of silicon-vacancy centers in single crystal diamond

Applied Physics Letters, 2015

Electrically driven emission from negatively charged silicon-vacancy (SiV) − centers in single crystal diamond is demonstrated. The SiV centers were generated using ion implantation into an i region of a p-i-n single crystal diamond diode. Both electroluminescence and the photoluminescence signals exhibit the typical emission that is attributed to the (SiV) − centers. Under forward and reversed biased PL measurements, no signal from the neutral (SiV) 0 defect could be observed. The realization of electrically driven (SiV) − emission is promising for scalable nanophotonics devices employing color centers in single crystal diamond. arXiv:1503.04778v1 [cond-mat.mtrl-sci]

Electronic structure of the N-V center in diamond: Experiments

Physical review. B, Condensed matter, 1996

Quantum-beat spectroscopy has been used to observe excited states of the N-V center in diamond. For the 1.945-eV optical transition, direct evidence is presented for the existence of GHz-scale fine structure, together with a much larger 46-cm Ϫ1 level splitting in the E state. An interference effect observed in transient fourwave-mixing response is explained with a polarization selection rule involving Zeeman coherence among magnetic sublevels. Also, detailed dephasing measurements versus temperature and wavelength have identified the decay mechanisms operative among the various states. A comparison of these results with ab initio calculations of excited electronic structure and interactions based on several multielectron models supports the conclusion that the N-V center is a neutral, two-electron center governed by a strong Jahn-Teller effect and weak spin-spin interactions.

Details of a theoretical model for electronic structure of the diamond vacancies

2004

A new model to calculate electronic states of the diamond vacancies has been developed using many body techniques. This model is based on physical assumptions of previous molecular models but does not use configuration interaction. Present model allows an accurate and unified treatment of electronic levels and related eigen functions for diamond vacancies, in addition to transition energies of the first dipole-allowed transitions in the neutral (V 0) and negatively charged (V À) vacancies, GR1 and ND1 band. For the first time, we calculated their optical transition intensities. For obtaining these results, we solved a generalized form of the Hubbard Hamiltonian, which consists of all electron-electron interaction terms on atomic orbital basis. Spatial symmetry of the defect, T d symmetry, is included in the form of the Hamiltonian, and the eigen states have automatically the correct spin and symmetry properties. We discuss the possibility of the reduction of the wide gap between theoretical and semiempirical wisdom by including deformation of the dangling orbital or delocalization of the vacancy electrons to the next nearest neighbor (NNN) atoms of the vacancies. Our prediction for low lying the 3 T 1 level of the neutral vacancy in diamond is consistent with experimental expectations. We report the variation of the ground and excited states of the GR1 and ND1 lines with hopping parameter t and also the electronic configurations of these states.

Nitrogen-vacancy center in diamond: Model of the electronic structure and associated dynamics

Physical Review B, 2006

Symmetry considerations are used in presenting a model of the electronic structure and the associated dynamics of the nitrogen-vacancy center in diamond. The model accounts for the occurrence of optically induced spin polarization, for the change of emission level with spin polarization and for new measurements of transient emission. The rate constants given are in variance to those reported previously.

Properties of nitrogen-vacancy centers in diamond: the group theoretic approach

We present a procedure that makes use of group theory to analyze and predict the main properties of the negatively charged nitrogen-vacancy (NV) center in diamond. We focus on the relatively low temperatures limit where both the spin-spin and spin-orbit effects are important to consider. We demonstrate that group theory may be used to clarify several aspects of the NV structure, such as ordering of the singlets in the (e 2 ) electronic configuration, the spin-spin and the spin-orbit interactions in the (ae) electronic configuration. We also discuss how the optical selection rules and the response of the center to electric field can be used for spin-photon entanglement schemes. Our general formalism is applicable to a broad class of local defects in solids. The present results have important implications for applications in quantum information science and nanomagnetometry.