title: Hyperentanglement-enabled direct characterization of quantum dynamics.
abstract: We use hyperentangled photons to experimentally implement an entanglement-assisted quantum process tomography technique known as direct characterization of quantum dynamics. Specifically, hyperentanglement-assisted Bell-state analysis enabled us to characterize a variety of single-qubit quantum processes using far fewer experimental configurations than are required by standard quantum process tomography. Furthermore, we demonstrate how known errors in Bell-state measurement may be compensated for in the data analysis. Using these techniques, we have obtained single-qubit process fidelities over 98% but with one-third the number of experimental configurations required for standard quantum process tomography. Extensions of these techniques to multiqubit quantum processes are discussed.
authors: Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA.
authors: T M
authors: TM
authors: Graham
authors: J T
authors: JT
authors: Barreiro
authors: M
authors: M
authors: Mohseni
authors: P G
authors: PG
authors: Kwiat