Circuit Quantum Electrodynamics: Single Microwave Photons on Demand Superconducting qubits to flying qubits R.J. Schoelkopf, M.H. Devoret and S.M. Girvin; Yale University DMR 0653377 and DMR 0603369

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Circuit Quantum Electrodynamics Single
Microwave Photons on DemandSuperconducting
qubits to flying qubitsR.J. Schoelkopf, M.H.
Devoret and S.M. Girvin Yale UniversityDMR
0653377 and DMR 0603369
cavity
Cavity QEDan atom trapped between mirrors

qubit
Measured Control pulse
Integrated circuit in which a superconducting
qubit, or artificial atom, is coupled to
microwave photons trapped in a super-conducting
transmission line cavity, in direct analogy
with the field of cavity quantum electrodynamics
(cavity QED) in quantum optics.
Measured Fluorescence
First observation of single microwave photons on
demand. The control pulse Rabi flops the qubit
and if the qubit ends up in the excited state, it
decays, emitting exactly one microwave photon.
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Flying QubitsR.J. Schoelkopf, M.H. Devoret and
S.M. Girvin Yale UniversityDMR 0653377 and DMR
0603369
Education Postdoctoral Fellows Andrew Houck,
Hannes Majer, Jay Gambetta, Andreas
Wallraff Graduate Students David Schuster, Joe
Schreier, Blake Johnson, Jerry Chow, Lev Bishop,
Terri Yu, Emily Chan Undergraduates This
project has formed parts of six senior theses at
Yale by Sameer Kumar 04, Clifford Cheung 04,
Will Braff 05, Joe Chen 06, Jared Schwede 07,
Daniel Rubin 07. Publications Resolving Single
Photon States in a Superconducting Circuit, D.I.
Schuster, A.A. Houck, et al., Nature 445, 515
(2007). Generating Single Microwave Photons in a
Circuit, A. A. Houck, D. I. Schuster, et al.,
Nature (in press) cond-mat/0702648. Coupling
Superconducting Qubits via a Cavity Bus, J.
Majer, J.M. Chow, et al., Nature (in press).
Fluorescence tomography showing that the
quantum state of the qubit has been mapped onto
the quantum state of the microwave field.
Impact This experiment and the new paradigm of
circuit quantum electrodynamics creates many
possibilities for doing quantum optics with
circuits in an ultra-strong coupling regime not
accessible with traditional atomic physics
methods.