Quantum Simulation of the Bosonic Creutz Ladder with a Parametric Cavity

TL;DR

This paper demonstrates a superconducting parametric cavity used as an efficient quantum simulator to emulate a bosonic Creutz ladder, showcasing complex hopping interactions and topological features in a programmable synthetic lattice.

Contribution

It introduces a novel hardware-efficient analog quantum simulator using a multimode superconducting cavity for simulating lattice models with complex interactions.

Findings

Successful simulation of a bosonic Creutz ladder plaquette.

Reconstruction of the experimental Hamiltonian from scattering data.

Observation of topological features in the synthetic lattice.

Abstract

There has been a growing interest in realizing quantum simulators for physical systems where perturbative methods are ineffective. The scalability and flexibility of circuit quantum electrodynamics (cQED) make it a promising platform to implement various types of simulators, including lattice models of strongly-coupled field theories. Here, we use a multimode superconducting parametric cavity as a hardware-efficient analog quantum simulator, realizing a lattice in synthetic dimensions with complex hopping interactions. The coupling graph, \textit{i.e.} the realized model, can be programmed \textit{in situ}. The complex-valued hopping interaction further allows us to simulate, for instance, gauge potentials and topological models. As a demonstration, we simulate a plaquette of the bosonic Creutz ladder. We characterize the lattice with scattering measurements, reconstructing the experimental Hamiltonian and observing emerging topological features. This platform can be easily extended to larger lattices and different models involving other interactions.