Rydberg atoms and superconducting qubits - a hybrid cavity QED interface
Klaus F. Reim1, S. Filipp1, T. Thiele1, A. Wallraff1, S. D. Hogan^2, P. Allmendinger2, J. A. Agner2, and F. Merkt2
1 Quantum Device Lab, ETH Zürich, Switzerland
2 Laboratorium für Physikalische Chemie, ETH Zürich, Switzerland
We present a hybrid quantum system that interfaces superconducting on-chip microwave technology with Rydberg atoms. Our motivation for this interdisciplinary project is the combination of the best properties of both worlds, namely the fast on-chip quantum processing capabilities of the solid state architecture and the long storage times of Rydberg atoms, which could potentially serve as a quantum memory for a future quantum computer.
We demonstrate coherent interactions between a co-planar microwave waveguide and Rydberg atoms. The observed Rabi oscillations between neighboring Rydberg states affirm that there is significant coupling between the microwave field and the Rydberg atoms. The temporal decay of the Rabi oscillations is used to identify limitations to the lifetime of the Rydberg atoms.
In future experiments the co-planar transmission line will be replaced by a superconducting transmission line fabricated on a single-crystal substrate. The designated goal is to reduce the effect of stray electric fields from surface imperfections. In addition, collimation and guiding elements will be realized on-chip to gain control over the atom-surface distance and the size of the Rydberg ensemble.