Tunable Nonadiabatic Excitation in a Single-Electron Quantum Dot

ArticleinPhysical Review Letters 106(12):126801 · March 2011with7 Reads
Impact Factor: 7.51 · 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.