A novel package for fast-flux delivery in 3D

Parametric flux modulation of SQUIDs and other flux-tunable devices has shown great promise in engineering fast gate operations and nonlinear quantum interactions. However, its applications have been primarily limited to 2D planar architectures. The efficient delivery of fast flux modulation in 3D architectures, potentially allowing the integration of fast parametric interactions with highly coherent 3D quantum memories, has been a tempting yet challenging task. Here we propose a novel design that allows such an efficient delivery of dc and ac flux into a 3D superconducting package without driving the charge degree of freedom, while preserving the coherence properties of the device. As an example, we show how our design enables the parametric modulation of a dc SQUID device, and demonstrate how high-fidelity operations can be achieved.