Many-body quantum circuits for quantum simulation and computing

  1. Samuel A. Wilkinson,
  2. and Michael J. Hartmann
Quantum simulators are attractive as a means to study many-body quantum systems that are not amenable to classical numerical treatment. A versatile framework for quantum simulation
is offered by superconducting circuits. In this perspective, we discuss how superconducting circuits allow the engineering of a wide variety of interactions, which in turn allows the simulation of a wide variety of model Hamiltonians. In particular we focus on strong photon-photon interactions mediated by nonlinear elements. This includes on-site, nearest-neighbour and four-body interactions in lattice models, allowing the implementation of extended Bose-Hubbard models and the toric code. We discuss not only the present state in analogue quantum simulation, but also future perspectives of superconducting quantum simulation that open up when concatenating quantum gates in emerging quantum computing platforms.

Linear response theory of Josephson junction arrays in a microwave cavity

  1. Samuel A. Wilkinson,
  2. and Jared H. Cole
Motivated by recent experiments on Josephson junction arrays in microwave cavities, we construct a quantum phase model and calculate the susceptibility of this model in linear response.
Both charge and vortex degrees of freedom are considered, as well as circuits containing either Josephson junctions or coherent quantum phase slip elements. The effects of decoherence are considered via a Lindblad master equation.