Probing two driven double quantum dots strongly coupled to a cavity

TL;DR

This paper investigates strongly driven double quantum dots coupled to a cavity, developing a new theoretical model that captures complex hybrid states and enables exploration of multi-qubit systems in the strong coupling regime.

Contribution

The authors introduce a comprehensive theory for strongly driven hybrid quantum systems, extending analysis beyond the dispersive regime and applicable to multi-qubit configurations.

Findings

Measured fringes match theoretical predictions

Enlarged splittings of hybrid Floquet states observed

Model successfully describes multi-qubit strong coupling phenomena

Abstract

We experimentally and theoretically study a driven hybrid circuit quantum electrodynamics (cQED) system beyond the dispersive coupling regime. Treating the cavity as part of the driven system, we develop a theory applicable to such strongly coupled and to multi-qubit systems. The fringes measured for a single driven double quantum dot (DQD)-cavity setting and the enlarged splittings of the hybrid Floquet states in the presence of a second DQD are well reproduced with our model. This opens a path to study Floquet states of multi-qubit systems with arbitrarily strong coupling and reveals a new perspective for understanding strongly driven hybrid systems.