Fano resonance in electron transport through single dopant atoms

Antiresonances are observed in electron transport through a resonant dopant atom situated near a metal-semiconductor interface in a Schottky barrier metal-oxide-semiconductor field-effect transistor. The lineshapes do not significantly change in magnetic fields up to 5 T, but are modified by small dc bias voltages. We argue that these effects are the result of quantum interference between two tunneling paths and can be explained in the context of a Fano lineshape.