Color center formation in silicon crystals with intense ion pulses from laser-plasma acceleration*

We report on studies of defect evolution and color center formation in silicon single crystals during the interaction with intense ion pulses from laser-plasma acceleration.  Ion pulses, including protons and carbon ions with energies up to several MeV, are generated when fs-laser pulses impinge on thin foils with intensities of ~10^19 W/cm^2 [1].  We characterize ion species and energy distributions and correlate resulting defects and color centers in photoluminescence measurements.  W- and G-center type color centers are formed with relative intensities that vary as a function of local ion flux conditions.  We use density functional theory to calculate color center linewidths as a function of local disorder.  Color centers form when a proton pulse pre-heats a sample, followed a few ns later by implantation and drive-in diffusion of low energy carbon ions.  We discuss potential applications of this form of local color center synthesis for the development of spin-photon qubits.  

[1] S. Steinke, et al., “Acceleration of high charge ion beams with achromatic divergence by petawatt laser pulses”, Phys. Rev. Accel. and Beams 23,021302 (2020)