title: Two-dimensional lattice gauge theories with superconducting quantum circuits.
abstract: A quantum simulator of [Formula: see text] lattice gauge theories can be implemented with superconducting circuits. This allows the investigation of confined and deconfined phases in quantum link models, and of valence bond solid and spin liquid phases in quantum dimer models. Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well. Here we show how state-of-the-art superconducting technology allows us to simulate these phenomena in relatively small circuit lattices. By exploiting the strong non-linear couplings between quantized excitations emerging when superconducting qubits are coupled, we show how to engineer gauge invariant Hamiltonians, including ring-exchange and four-body Ising interactions. We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories. The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.
authors.affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.
authors.forename: D
authors.initials: D
authors.lastname: Marcos
authors.affiliation: Albert Einstein Center, Institute for Theoretical Physics, Bern University, CH-3012, Bern, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Widmer
authors.affiliation: IPCMS (UMR 7504) and ISIS (UMR 7006), University of Strasbourg and CNRS, 67000 Strasbourg, France.
authors.forename: E
authors.initials: E
authors.lastname: Rico
authors.affiliation: Joint Quantum Institute, NIST/University of Maryland, College Park 20742, USA ; Department of Electrical Engineering and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hafezi
authors.affiliation: Institute of Atomic and Subatomic Physics, TU Wien, Stadionallee 2, 1020 Wien, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Rabl
authors.affiliation: Albert Einstein Center, Institute for Theoretical Physics, Bern University, CH-3012, Bern, Switzerland.
authors.forename: U-J
authors.initials: UJ
authors.lastname: Wiese
authors.affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria ; Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Zoller
keywords: Gauge theories; Quantum simulation; Superconducting qubits