Hybrid Quantum Systems

Hybrid Quantum Systems

In conjunction with the Schuster Lab, we are working to combine the strengths of disparate quantum-coherent systems to realize hybrid systems with unique properties, and devices with unique capabilities. This requires developing extremely high-fidelity tools to interface the systems with one another, thereby maintaining coherence through repeated interconversion of the quantum state from one system to another.

Approach

• We have developed a platform capable of achieving quantum-limited transduction of single photons, between optical and mmwave regimes, using Rydberg atoms as the transducer.
• The mm/micro wave photons may be directly coupled to Josephson junctions to realize extremely strong nonlinearities, to realize quantum gates and spin models, while the optical photons may be easily read out for state-tomography purposes, or transported over long distances for quantum-secured communication.
• On the technical side, mm-wave photons enter the quantum regime at ~Kelvin temperatures, so our experiments do not require dilution refrigerators, only 2-4K pulse tubes. Furthermore, a typical Rydberg atom has mm-wave (~100GHz) large-dipole-moment transitions near the n=30 Rydberg state, making it much less sensitive to stray electric fields than similar efforts in the microwave domain, where the atoms must be excited to nearly n=100.
• Looking ahead, we intend to harness the extreme single-atom mmwave cooperativities to achieve Heisenberg-limited spin-squeezing of the Rydberg atoms, for applications in quantum metrology.