Tunable High-Q Superconducting mm-Wave Cavities

SUMMARY

• Cavity and circuit quantum electrodynamics systems provide unprecedented control over photonic quantum states via coupling to strongly nonlinear single emitters. The millimeter (mm) wave frequency band is of great interest for quantum devices, as high-fidelity quantum emitters—such as Rydberg atoms, molecules, and silicon vacancies—exhibit resonances in these bands. High-Q resonators at these frequencies would give access to strong interactions between emitters and single photons, leading to rich and unexplored quantum phenomena at moderate temperatures.

• Prior efforts in this field have been confined to studies concerned with Rydberg cavity quantum electrodynamics followed closely by cavity and circuit quantum electrodynamics systems, which have become essential tools for exploring quantum phenomena in both the optical and microwave regimes. Hybrid systems, which cross-couple these regimes, can harness the strengths of optical systems for communication and microwave systems for quantum information processing, yielding a more powerful toolset for quantum information technology. In particular, the coherent interconversion of microwave and optical photons would enable large quantum networks and robust transfer of quantum information.

• The faculty inventor developed a hybrid system through a three-dimensional mm-wave cavity with a measured resonance in the mm-wave frequency band, sufficient to reach strong coupling in a Rydberg cavity quantum electrodynamics system.  The inventors have demonstrated in situ tunability along with coupling to specific atomic transitions. The resonator design is enabled through the realization that intersections of 3D waveguides support tightly confined bound states below the waveguide cutoff frequency. Harnessing the features of the cavity design, the inventors demonstrate a hybrid mm-wave and optical cavity, designed for interconversion and entanglement of mm-wave and optical photons using Rydberg atoms.

FIGURE

ADVANTAGES

ADVANTAGES

• Seamless and optically accessible resonator design
• Unique optical and electronic properties
• Small volume
• Simple fabrication

APPLICATIONS

• Quantum computing/quantum information processing
• Quantum electrodynamics
• Communication networks

June 16, 2023

Proof of concept

Patent Issued

Licensing,Co-development

David Schuster