title: Measurement of geometric phase for mixed states using single photon interferometry.
abstract: Geometric phase may enable inherently fault-tolerant quantum computation. However, due to potential decoherence effects, it is important to understand how such phases arise for mixed input states. We report the first experiment to measure mixed-state geometric phases in optics, using a Mach-Zehnder interferometer, and polarization mixed states that are produced in two different ways: decohering pure states with birefringent elements; and producing a nonmaximally entangled state of two photons and tracing over one of them, a form of remote state preparation.
authors.affiliation: Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: Ericsson
authors.forename: Daryl
authors.initials: D
authors.lastname: Achilles
authors.forename: Julio T
authors.initials: JT
authors.lastname: Barreiro
authors.forename: David
authors.initials: D
authors.lastname: Branning
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Peters
authors.forename: Paul G
authors.initials: PG
authors.lastname: Kwiat