title: Observation of Berry's phase in a solid-state qubit.
abstract: In quantum information science, the phase of a wave function plays an important role in encoding information. Although most experiments in this field rely on dynamic effects to manipulate this information, an alternative approach is to use geometric phase, which has been argued to have potential fault tolerance. We demonstrated the controlled accumulation of a geometric phase, Berry's phase, in a superconducting qubit; we manipulated the qubit geometrically by means of microwave radiation and observed the accumulated phase in an interference experiment. We found excellent agreement with Berry's predictions and also observed a geometry-dependent contribution to dephasing.
authors.affiliation: Department of Physics, Eidgenössische Technische Hochschule (ETH) Zürich, Schafmattstrasse 16, 8093 Zürich, Switzerland. leek@phys.ethz.ch
authors.forename: P J
authors.initials: PJ
authors.lastname: Leek
authors.forename: J M
authors.initials: JM
authors.lastname: Fink
authors.forename: A
authors.initials: A
authors.lastname: Blais
authors.forename: R
authors.initials: R
authors.lastname: Bianchetti
authors.forename: M
authors.initials: M
authors.lastname: Göppl
authors.forename: J M
authors.initials: JM
authors.lastname: Gambetta
authors.forename: D I
authors.initials: DI
authors.lastname: Schuster
authors.forename: L
authors.initials: L
authors.lastname: Frunzio
authors.forename: R J
authors.initials: RJ
authors.lastname: Schoelkopf
authors.forename: A
authors.initials: A
authors.lastname: Wallraff