title: Observation of nonadditive mixed-state phases with polarized neutrons.
abstract: In a neutron polarimetry experiment the mixed-state relative phases between spin eigenstates are determined from the maxima and minima of measured intensity oscillations. We consider evolutions leading to purely geometric, purely dynamical, and combined phases. It is experimentally demonstrated that the sum of the individually determined geometric and dynamical phases is not equal to the associated total phase which is obtained from a single measurement, unless the system is in a pure state.
authors.affiliation: Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Klepp
authors.forename: Stephan
authors.initials: S
authors.lastname: Sponar
authors.forename: Stefan
authors.initials: S
authors.lastname: Filipp
authors.forename: Matthias
authors.initials: M
authors.lastname: Lettner
authors.forename: Gerald
authors.initials: G
authors.lastname: Badurek
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hasegawa