title: Accurate and Robust Unitary Transformations of a High-Dimensional Quantum System.
abstract: Unitary transformations are the most general input-output maps available in closed quantum systems. Good control protocols have been developed for qubits, but questions remain about the use of optimal control theory to design unitary maps in high-dimensional Hilbert spaces, and about the feasibility of their robust implementation in the laboratory. Here we design and implement unitary maps in a 16-dimensional Hilbert space associated with the 6S(1/2) ground state of (133)Cs, achieving fidelities >0.98 with built-in robustness to static and dynamic perturbations. Our work has relevance for quantum information processing and provides a template for similar advances on other physical platforms.
authors.affiliation: Center for Quantum Information and Control, College of Optical Sciences and Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.|National Institute of Standards and Technology and Joint Quantum Institute, NIST and the University of Maryland, Gaithersburg, Maryland 20899, USA.
authors.forename: B E
authors.initials: BE
authors.lastname: Anderson
authors.affiliation: Center for Quantum Information and Control, College of Optical Sciences and Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: H
authors.initials: H
authors.lastname: Sosa-Martinez
authors.affiliation: Center for Quantum Information and Control, Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA.|Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: C A
authors.initials: CA
authors.lastname: Riofrío
authors.affiliation: Center for Quantum Information and Control, Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Ivan H
authors.initials: IH
authors.lastname: Deutsch
authors.affiliation: Center for Quantum Information and Control, College of Optical Sciences and Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Poul S
authors.initials: PS
authors.lastname: Jessen