Top-gated few-electron double quantum dot in Si/SiGe

A few-electron quantum dot utilizing Schottky, metal top gates in a modulation doped Si/SiGe heterostructure was realized and non-linear transport through the dot was studied. By carefully tuning the capacitively coupled gates, the single quantum dot was transformed into two tunnel-coupled quantum dots in series. The resulting double quantum dot was tuned to the few-electron regime and the charge stability diagram was studied as a function of the gate voltages. Understanding of such a double dot system is essential for the practical implementation of exchange-mediated multi-qubit systems in silicon devices.