Superradiance with an ensemble of superconducting flux qubits

TL;DR

This paper proposes a method to reduce inhomogeneous broadening in large ensembles of superconducting flux qubits and demonstrates how to observe superradiance, enabling exploration of quantum many-body physics with superconducting circuits.

Contribution

It introduces a tunable technique to minimize inhomogeneous broadening and a tailored control pulse to observe superradiance in flux qubit ensembles.

Findings

Minimized inhomogeneous broadening by tuning external flux.

Demonstrated superradiance with quadratic scaling in flux qubit ensembles.

Enabled exploration of quantum many-body phenomena using superconducting circuits.

Abstract

Superconducting flux qubits are a promising candidate for realizing quantum information processing and quantum simulations. Such devices behave like artificial atoms, with the advantage that one can easily tune the "atoms" internal properties. Here, by harnessing this flexibility, we propose a technique to minimize the inhomogeneous broadening of a large ensemble of flux qubits by tuning only the external flux. In addition, as an example of many-body physics in such an ensemble, we show how to observe superradiance, and its quadratic scaling with ensemble size, using a tailored microwave control pulse that takes advantage of the inhomogeneous broadening itself to excite only a sub-ensemble of the qubits. Our scheme opens up an approach to using superconducting circuits to explore the properties of quantum many-body systems.