Detection of a persistent-current qubit by resonant activation
  We present the implementation of a new scheme to detect the quantum state of a persistent-current qubit. It relies on the dependency of the measuring Superconducting Quantum Interference Device (SQUID) plasma frequency on the qubit state, which we detect by resonant activation. With a measurement pulse of only 5ns, we observed Rabi oscillations with high visibility (65%). 
P. Bertet, I. Chiorescu, K. Semba, C.J.P.M Harmans, J.E. Mooij