Tunable nonadiabatic excitation in a single-electron quantum dot.

National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom.
Physical Review Letters (Impact Factor: 7.73). 03/2011; 106(12):126801. DOI: 10.1103/PhysRevLett.106.126801
Source: PubMed

ABSTRACT We report the observation of nonadiabatic excitations of single electrons in a quantum dot. Using a tunable-barrier single-electron pump, we have developed a way of reading out the excitation spectrum and level population of the dot by using the pump current as a probe. When the potential well is deformed at subnanosecond time scales, electrons are excited to higher levels. In the presence of a perpendicular magnetic field, the excited states follow a Fock-Darwin spectrum. Our experiments provide a simple model system to study nonadiabatic processes of quantum particles.

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