Optimization of light-emitting defects in silicon with plasmas, ion beams, and lasers*

Light-emitting defects (or color centers) in semiconductors are promising qubit candidates for applications in quantum sensing and quantum communication.  Color centers often form when dopants are introduced into the host crystal matrix combined with energetic radiation and thermal annealing.  Quantum information science (QIS) applications benefit from high

quality color centers that can be formed reliably and this poses new challenges and opportunities for material processing including with ion beams and plasmas. We report on the synthesis of high-quality color centers using terawatt to petawatt laser-plasma-driven ion beams to implant selected elements including boron, titanium, and carbon into silicon. Color centers, including qubit candidates such as W, G, and C-centers in silicon, form directly under these conditions of laser-ion doping. 

Color center synthesis with the laser-ion plasma-driven approach complements and can be combined with processing methods including conventional ion implantation, thermal annealing, exposure to H₂ plasmas, and fs lasers for local formation and passivation of high-quality color centers. We outline directions toward scalable integration of color centers in silicon for applications in QIS.