Optical spectroscopy of xenon-related defects in diamond.

摘要

The work presents the results of optical studies of Xe-related defect in diamond. This defect is one of a few having narrow zero-phonon line in the near-infrared part of the photo-luminescence spectra. It appears in diamond after Xe+ ion implantation followed by thermal annealing. Given unique physical properties of diamond (hardness, optical transparency in wide spectral range, chemical inertness, high thermal conductivity, low thermal expansion coefficient) and stability of Xe-related center it can be viewed as an potential candidate for the source of single-photons, or as optically manipulated qubit, not unlike nitrogen-vacancy center. However, compared to the latter Xe-related center is not as well understood and it is necessary to gain thorough understanding of its spatial structure, symmetry, electronic states and mechanisms of interaction with the host diamond lattice.;This thesis addresses several questions, in regard to Xe-related center: 1) How efficiently this center is formed in the implantation/annealing process; 2) How does it interact with the host lattice to produce both homogeneous and inhomogeneous shape of the 811.7 nm zero-phonon line; and 3) What is the type and nature of transitions responsible for the 811.7 nm zero-phonon line.;In answering the first question two methods for measuring the conversion efficiency of any kind of optically active defect have been developed and applied to Xe-related center in diamond. The study of line-broadening mechanisms showed how this center interacts with the strain produced by other neighboring Xe-centers, distributed in a plane-like geometry. Also, interaction with vibrational motions of the diamond lattice localized in the vicinity of the Xe-centers is analyzed and the parameters of this pseudo-local mode are found. Finally, using the effects of optical saturation in photo-luminescence under excitation with Gaussian laser beams it has been shown that 811.7 nm zero-phonon line is due to absorption and emission by circular magnetic dipole. Also, the site symmetry of Xe-related center has been confirmed as trigonal with the threefold axis oriented along direction in the diamond crystal.