Color Center Qubit Synthesis with Ion Pulses from Laser-Plasma Acceleration*

We report on the formation of color centers, such as the G-center, a spin-photon qubit candidate in silicon, with ion pulses from laser-plasma acceleration at the BELLA PW laser (~10¹⁹ W/cm², up to 1 Hz).  Proton and carbon ion pulses with intensities in the 10¹² ions/shot range are characterized with a Thomson parabola for energies above 2 MeV.  We quantify the flux of lower energy ions through implantation into silicon followed by ex-situ analysis and find that carbon ions with energies below 2 MeV are implanted with fluences of 10¹⁴ - 10¹⁵ atoms/cm²/shot.  Intense ion pulses excite and heat targets, leading to the direct formation of color centers without consecutive thermal annealing [1].  We compute the electronic structure of color centers within density functional theory.  We discuss the potential impacts of this form of local qubit synthesis far from equilibrium.