Experimental Determination of the Dipole Orientation of Single Color Centers in Silicon Carbide

Abstract

Divacancy defect spins in silicon carbide (SiC) are one of the promising candidates for quantum network and quantum information processing due to their attractive optical and spin properties. Although efforts have been made to investigate their properties and coherent manipulations, little is known about the properties of the optical dipole moment’s orientation of these defects, which are critically important for fluorescence enhancement and quantum communication. In this study, we determined the dipole moment’s orientation of single divacancy defects in 4H polytype SiC (4H-SiC) using tightly focused radially and azimuthally polarized laser beams through confocal microscopy. We can extract polar and azimuthal angles of the dipole moment compared with the theoretically calculated two-dimensional fluorescence intensity distributions. The polarization of photoluminescence of these different defects is measured and analyzed for comparison. These results are critical for the highly efficient nanostructure-coupled enhancement of emission and quantum communication where the dipole moment’s orientation should be known.

Vector Magnetometry Based on Polarimetric Optically Detected Magnetic Resonance

“…We achieve an angular RMSE $${\mathrm{\Omega}}_{\mathrm{RMSE}}=(27.5\pm 2.1)^{\circ}$$ from the $$\langle 111 \rangle$$ crystal axes, which is larger than the typical uncertainties of a few degrees, when determining the orientation of single dipoles. [ 13,34,40,41 ] Possible reasons are fluorescence saturation, the usage of ensembles, inhomogeneous excitation and collection, imperfectly cut diamond faces, and crystal strain. The latter challenges require improved sample preparation techniques.…”

Metal-Dielectric Nanopillar Antenna-Resonators for Efficient Collected Photon Rate from Silicon Carbide Color Centers

“…locations acting as quantum wells (associated to PL5 and PL6 at 1042 nm and 1038 nm). Their excitation polarisation has been determined to be orthogonal to the c-axis ( ) for PL5 and parallel ( ) for PL6 [ 43 ]. These type of divacancies are an ideal candidate for magnetic sensing at ambient conditions.…”

Characterization methods for defects and devices in silicon carbide

“…Polarisation studies of the ZPL can reveal the symmetry and transition dipoles of the defect. 90 There are many PL signatures in SiC that have been reported but have not yet been assigned to a particular atomic defect. 80,81 Understanding the origins of these defects, their role in devices and their possible use in applications remains an extremely active and interesting area of research.…”

“…100 These devices enhance the emission count rates and spectral purity and channel the emission into single mode fibers or wave-guides with high collection efficiency. This is often an obstacle in materials such as SiC and diamond due to the high refractive index and dipole emission of these defects 90 . For example, the V Si defect has a single dipole along the c-axis so that emission is preferentially directed perpendicular to the c-axis (usually along the surface direction).…”