Laser writing of color centers in diamond for quantum technologies

Synopsis

The nitrogen-vacancy (NV) center is a defect in which two adjacent sites in diamond’s tetrahedral lattice of carbon atoms are replaced. One site contains a nitrogen atom instead of carbon while the other is vacant. In its negatively charged state, the NV center gains an extra electron from the lattice, forming a ground state spin system which can be polarized with 532-nm light, even at room temperature. One of the spin states fluoresces much more brightly than the others so that fluorescence can be used for spin-state readout. At the same time, the NV’s electron spin states are sensitive to magnetic and electric fields. These properties make NVs attractive both as a scalable platform for quantum information systems and for high sensitivity electromagnetic field quantum sensors. 

An integrated optics platform in diamond is essential for both quantum information systems and quantum sensing, where the NV is used as an optically detecting atomic probe. This is because of the ultimate stability and integration provided by monolithic waveguides, in addition to the potential for enhanced optical interaction with NVs. 

For the first time, 3D laser microprocessing is combined with ion implantation nanofabrication to exploit the advantages of both techniques to achieve integrated high quality quantum emitters and buried optical waveguides in diamond. Ion implantation is used to form NV quantum emitters at nanometric depths at the end facets of laser written optical waveguides. This hybrid fabrication scheme enables development of 2D quantum sensing arrays, facilitating spatially and temporally correlated magnetometry. This method is also applied to implant SiV, another promising quantum emitter, in laser written photonic circuits, to engineer light at the single photon level, which could enable next generation quantum computation systems in diamond.

Speaker Bio: Shane Eaton received the B.A.Sc. degree in engineering physics (electrical engineering option) from the University of British Columbia, Vancouver, BC, Canada, in 2002, and the Ph.D. degree in electrical engineering from the University of Toronto, Toronto, ON, Canada, in 2008.

During his undergraduate work, he had an internship job at Nortel Networks in Ottawa which inspired him to pursue an academic career in photonics. During his Ph.D., he studied the effect of repetition rate on thermal diffusion and heat accumulation during femtosecond laser writing of optical waveguides in glasses for applications in telecommunications and sensing. At IFN-CNR, his current research is femtosecond laser fabrication of micro-nano devices for quantum technologies.

He is an author or coauthor of 75 journal papers, 6 book chapters and over 100 conference papers. His h-index is 35 with 5000 citations.