Europhys. Lett.
Volume 76, Number 1, October 2006
Page(s) 22 - 28
Section Atomic and molecular physics
Published online 30 August 2006
Europhys. Lett., 76 (1), pp. 22-28 (2006)
DOI: 10.1209/epl/i2006-10232-4

Quantum state preparation in circuit QED via Landau-Zener tunneling

K. Saito1, M. Wubs2, S. Kohler2, P. Hänggi2 and Y. Kayanuma3

1  Department of Physics, Graduate School of Science, University of Tokyo Tokyo 113-0033, Japan
2  Institut für Physik, Universität Augsburg - D-86135 Augsburg, Germany
3  Department of Mathematical Science, Graduate School of Engineering Osaka Prefecture University - Sakai 599-8531, Japan

received 16 June 2006; accepted in final form 8 August 2006
published online 30 August 2006

We study a qubit undergoing Landau-Zener transitions enabled by the coupling to a circuit-QED mode. Summing an infinite-order perturbation series, we determine the exact nonadiabatic transition probability for the qubit, being independent of the frequency of the QED mode. Possible applications are single-photon generation and the controllable creation of qubit-oscillator entanglement.

32.80.Qk - Coherent control of atomic interactions with photons.
03.67.Lx - Quantum computation.
32.80.Bx - Level crossing and optical pumping.

© EDP Sciences 2006