Measurement induced dephasing of a superconducting qubit strongly coupled to a resonator

Recently, the solid state equivalent of a cavity QED system has been experimentally observed using a Cooper pair box as the artificial atom (qubit) and a transmission line resonator as the cavity [1]. This system is a good candidate for quantum computation as, in the dispersive limit, quantum control and readout can be achieved by multiplexing RF pulses [2]. In this talk only the readout scheme will be considered, in particular experimental [3] and theoretical results for the measurement induced dephasing will be presented.\newline [1] A. Wallraff, D. Schuster, A. Blais, L. Frunzio, R.-S. Huang, J. Majer, S. Kumar, S. M. Girvin and R. J. Schoelkopf, Nature {\bf 431}, 162 (2004).\newline [2] A. Blais, R.-S. Huang, A. Wallraff, S. M. Girvin and R. J. Schoelkopf, Phys. Rev. A {\bf 69}, 062320 (2004).\newline [3] D. Schuster, A. Wallraff, A. Blais, L. Frunzio, R.-S. Huang, J. Majer, S. M. Girvin and R. J. Schoelkopf, cond-mat/0408367.