title: An open-system quantum simulator with trapped ions.
abstract: The control of quantum systems is of fundamental scientific interest and promises powerful applications and technologies. Impressive progress has been achieved in isolating quantum systems from the environment and coherently controlling their dynamics, as demonstrated by the creation and manipulation of entanglement in various physical systems. However, for open quantum systems, engineering the dynamics of many particles by a controlled coupling to an environment remains largely unexplored. Here we realize an experimental toolbox for simulating an open quantum system with up to five quantum bits (qubits). Using a quantum computing architecture with trapped ions, we combine multi-qubit gates with optical pumping to implement coherent operations and dissipative processes. We illustrate our ability to engineer the open-system dynamics through the dissipative preparation of entangled states, the simulation of coherent many-body spin interactions, and the quantum non-demolition measurement of multi-qubit observables. By adding controlled dissipation to coherent operations, this work offers novel prospects for open-system quantum simulation and computation.
authors.affiliation: Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
authors.forename: Julio T
authors.initials: JT
authors.lastname: Barreiro
authors.forename: Markus
authors.initials: M
authors.lastname: Müller
authors.forename: Philipp
authors.initials: P
authors.lastname: Schindler
authors.forename: Daniel
authors.initials: D
authors.lastname: Nigg
authors.forename: Thomas
authors.initials: T
authors.lastname: Monz
authors.forename: Michael
authors.initials: M
authors.lastname: Chwalla
authors.forename: Markus
authors.initials: M
authors.lastname: Hennrich
authors.forename: Christian F
authors.initials: CF
authors.lastname: Roos
authors.forename: Peter
authors.initials: P
authors.lastname: Zoller
authors.forename: Rainer
authors.initials: R
authors.lastname: Blatt