title: Transport spectroscopy of non-equilibrium many-particle spin states in self-assembled quantum dots.
abstract: Self-assembled quantum dots (QDs) are prominent candidates for solid-state quantum information processing. For these systems, great progress has been made in addressing spin states by optical means. In this study, we introduce an all-electrical measurement technique to prepare and detect non-equilibrium many-particle spin states in an ensemble of self-assembled QDs at liquid helium temperature. The excitation spectra of the one- (QD hydrogen), two- (QD helium) and three- (QD lithium) electron configuration are shown and compared with calculations using the exact diagonalization method. An exchange splitting of 10 meV between the excited triplet and singlet spin states is observed in the QD helium spectrum. These experiments are a starting point for an all-electrical control of electron spin states in self-assembled QDs above liquid helium temperature.
authors.affiliation: Fakultät für Physik and CeNIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Marquardt
authors.forename: M
authors.initials: M
authors.lastname: Geller
authors.forename: B
authors.initials: B
authors.lastname: Baxevanis
authors.forename: D
authors.initials: D
authors.lastname: Pfannkuche
authors.forename: A D
authors.initials: AD
authors.lastname: Wieck
authors.forename: D
authors.initials: D
authors.lastname: Reuter
authors.forename: A
authors.initials: A
authors.lastname: Lorke
mesh_terms: D001330:Electronic Data Processing / Q000379:methods*; D004583:Electrons; D006371:Helium; D018625:Microscopy, Atomic Force; D045663:Quantum Dots; D013057:Spectrum Analysis / Q000379:methods*; D013696:Temperature
chemical_list: D006371:Helium