Laser-ion-doping and qubit synthesis in semiconductors*

Intense ion pulses from laser acceleration can damage, dope, heat and anneal semiconductors in one step. Excitation during nanosecond ion pulses is followed by rapid quenching on a microsecond time scale where desired phases and defect structures can stabilize. We report on direct formation of quantum defects in silicon and diamond samples processed with ion pulses from laser acceleration at the BELLA Center [1] and at the PHELIX facility (GSI) [2]. We characterized the ex situ quantum defect optical spectra, structural and compositional changes in the samples. In situ time-resolved ion current measurements at the BELLA Center 100 TW laser show a dual pulse structure with MeV ions from target normal sheath acceleration, followed by low energy ions from plasma expansion of the laser foil. Boron concentrations up to several atomic percent are observed in the samples from PW shots with boron foils, which enable the formation of a superconducting phase. We will discuss next steps in laser-ion doping optimization and color center qubit integration based on our recent results [1-5].