Probing remote entanglement in a localized system with a superconducting qubit quantum simulator.

Predicting the dynamics of quantum systems is a primary example of an intensive computational task that could be efficiently solved with a near term quantum computer.
To pursue this goal, we have fabricated a 9-qubit linear chain device made of superconducting circuits with nearest neighbor couplings. Our device is unique because it features frequency tunable qubits and an adjustable inter-qubit coupling strength, making it well suited to the simulation of quantum systems. We use the device to generate high-fidelity, multi-qubit, analog dynamics evolving under a Bose-Hubbard Hamiltonian.
In this talk, we discuss the calibration of this device for quantum simulation. Once calibrated we use this device to probe the basic physics of thermalization. Specifically, we use transport measurements to distinguish localized and diffusive behavior. To complement this, we use echo techniques to characterize the propagation of entanglement in these regimes. This shows qualitative differences between how energy and entropy flow in the system.