Time-Resolved Photoionization Detection of a Single Er³⁺ Ion in Silicon

The detection of charge trap ionization induced by resonant excitation enables spectroscopy on single Er3+ ions in silicon nanotransistors. In this work, a time-resolved detection method is developed to investigate the resonant excitation and relaxation of a single Er3+ ion in silicon. The time-resolved detection is based on a long-lived current signal with a tunable reset and allows the measurement under stronger and shorter resonant excitation in comparison to time-averaged detection. Specifically, the short-pulse study gives an upper bound of 23.7 mu s on the decay time of the I-4(13/2) state of the Er3+ ion. The fast decay and the tunable reset allow faster repetition of the single-ion detection, which is attractive for implementing this method in large-scale quantum systems of single optical centers. The findings on the detection mechanism and dynamics also provide an important basis for applying this technique to detect other single optical centers in solids.