title: Collapse of the spin-singlet phase in quantum dots.
abstract: We present experimental and theoretical results on a new regime in quantum dots in which the filling factor two-singlet state is replaced by new spin polarized phases. We make use of spin blockade spectroscopy to identify the transition to this new regime as a function of the number of electrons. The key experimental observation is a reversal of the phase in the systematic oscillation of the amplitude of Coulomb blockade peaks as the number of electrons is increased above a critical number. It is found theoretically that correlations are crucial to the existence of the new phases.
authors.affiliation: Institute for Microstructural Science, Research Council of Canada, Ottawa, Canada K1A OR6.
authors.forename: M
authors.initials: M
authors.lastname: Ciorga
authors.forename: A
authors.initials: A
authors.lastname: Wensauer
authors.forename: M
authors.initials: M
authors.lastname: Pioro-Ladriere
authors.forename: M
authors.initials: M
authors.lastname: Korkusinski
authors.forename: J
authors.initials: J
authors.lastname: Kyriakidis
authors.forename: A S
authors.initials: AS
authors.lastname: Sachrajda
authors.forename: P
authors.initials: P
authors.lastname: Hawrylak