Atomic-scale control of tunneling in few-donor quantum dots

Donor-based quantum devices in silicon are a promising candidate for spin-based solid-state quantum computing and analog quantum simulation. Carefully designing the tunneling strength in tunnel-coupled quantum dots is critical to high fidelity performance of spin initialization, readout, spin-exchange operations. This presentation covers our results in atomic-scale control and characterization of tunneling in STM-patterned devices in the few-donor quantum dots regime. We present resonant tunneling spectroscopy analysis of the tunnel junctions in few-donor single-electron transistors and double-dot devices where the tunnel gaps are defined at the atomic-scale. We characterize the tunneling rates between few-donor quantum dots and atomically aligned single electron charge sensors and report their impact on spin-selective tunneling for spin initialization and readout in few-donor quantum dots.