title: Tunable nonadiabatic excitation in a single-electron quantum dot.
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.
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Kataoka
authors.forename: J D
authors.initials: JD
authors.lastname: Fletcher
authors.forename: P
authors.initials: P
authors.lastname: See
authors.forename: S P
authors.initials: SP
authors.lastname: Giblin
authors.forename: T J B M
authors.initials: TJ
authors.lastname: Janssen
authors.forename: J P
authors.initials: JP
authors.lastname: Griffiths
authors.forename: G A C
authors.initials: GA
authors.lastname: Jones
authors.forename: I
authors.initials: I
authors.lastname: Farrer
authors.forename: D A
authors.initials: DA
authors.lastname: Ritchie