Gate-induced ionization of single dopant atoms

Gate-induced wave function manipulation of a single dopant atom is a possible basis of atomic scale electronics. From this perspective, we analyzed the effect of a small nearby gate on a single dopant atom in a semiconductor up to field ionization. The dopant is modelled as a hydrogen-like impurity and the Schrodinger equation is solved by a variational method. We find that--depending on the separation of the dopant and the gate--the electron transfer is either gradual or abrupt, defining two distinctive regimes for the gate-induced ionization process.