arXiv subjects

L. J. Rogers

Publications and source records attributed to L. J. Rogers.

4 recordsLinked to original sources

arXiv2015

Spectroscopy of Surface-Induced Noise Using Shallow Spins in Diamond

We report on the noise spectrum experienced by few nanometer deep nitrogen-vacancy centers in diamond as a function of depth, surface coating, magnetic field and temperature. Analysis reveals a double-Lorentzian noise spectra consistent with a surface electronic spin bath, with slower dynamics due to spin-spin interactions and faster dynamics related to phononic coupling. These results shed new light on the mechanisms responsible for surface noise affecting shallow spins at semiconductor interfaces, and suggests possible directions for further studies. We demonstrate dynamical decoupling from the surface noise, paving the way to applications ranging from nanoscale NMR to quantum networks.

quant-ph↗

arXiv2013

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.

cond-mat.mtrl-sci↗

arXiv2009

Low temperature studies of the excited-state structure of Nitrogen-Vacancy color centers in diamond

We report a study of the 3E excited-state structure of single nitrogen-vacancy (NV) defects in diamond, combining resonant excitation at cryogenic temperatures and optically detected magnetic resonance. A theoretical model of the excited-state structure is developed and shows excellent agreement with experimental observations. Besides, we show that the two orbital branches associated with the 3E excited-state are averaged when operating at room temperature. This study leads to an improved physical understanding of the NV defect electronic structure, which is invaluable for the development of diamond-based quantum information processing.

quant-ph↗

arXiv2008

New infrared emission of the NV centre in diamond: Zeeman and uniaxial stress studies

An emission band in the infrared is shown to be associated with a transition within the negative nitrogen-vacancy center in diamond. The band has a zero-phonon line at 1046 nm, and uniaxial stress and magnetic field measurements indicate that the emission is associated with a transition between 1E and 1A1 singlet levels. Inter-system crossing to these singlets causes the spin polarisation that makes the NV- centre attractive for quantum information processing, and the infrared emission band provides a new avenue for using the centre in such applications.

cond-mat.mtrl-sci↗