Assignment of the NV0 575 nm zero-phonon line in diamond to a 2E-2A2 transition

The time-averaged emission spectrum of single nitrogen-vacancy defects in diamond gives zero-phonon lines of both the negative charge state at 637 nm (1.945 eV) and the neutral charge state at 575 nm (2.156 eV). This occurs through photo-conversion between the two charge states. Due to strain in the diamond the zero-phonon lines are split and it is found that the splitting and polarization of the two zero-phonon lines are the same. From this observation and consideration of the electronic structure of the nitrogen-vacancy center it is concluded that the excited state of the neutral center has A2 orbital symmetry. The assignment of the 575 nm transition to a 2E - 2A2 transition has not been established previously.Comment: 5 pages, 5 figure

Charge switching dynamics and optimal excitation wavelength of single NV centers in ultrapure diamond

Photoluminescence excitation spectra of single NV centers in diamond are studied and an optimal wavelength for NV is found. The physics of bidirectional switching between NV0 and NV charge states of the defect is elucidated

Optimum photoluminescence excitation and recharging cycle of single nitrogen-vacancy centers in ultrapure diamond

Important features in the spectral and temporal photoluminescence excitation of single nitrogen-vacancy (NV) centers in diamond are reported at conditions relevant for quantum applications. Bidirectional switching occurs between the neutral (NV0) and negatively charged (NV -) states. Luminescence of NV - is most efficiently triggered at a wavelength of 575nm which ensures optimum excitation and recharging of NV0. The dark state of NV - is identified as NV0. A narrow resonance is observed in the excitation spectra at 521nm, which mediates efficient conversion to NV0

Charge switching dynamics and optimal excitation wavelength of single NV centers in ultrapure diamond

Photoluminescence excitation spectra of single NV centers in diamond are studied and an optimal wavelength for NV- is found. The physics of bidirectional switching between NV0 and NV- charge states of the defect is elucidated