Rabi oscillations of a qubit coupled to a two-level system
Y. M. Galperin, Daniil V. Shantsev, Joakim Bergli, B. L. Altshuler · Europhysics Letters (EPL) · 2005
The problem of Rabi oscillations in a qubit coupled to a fluctuator and in contact with a heath bath is considered. A scheme is developed for taking into account both phase and energy relaxation in a phenomenological way, while taking full account of the quantum dynamics of the four-level system subject to a driving AC field. Significant suppression of the Rabi oscillations is found when the qubit and fluctuator are close to resonance. The effect of the fluctuator state on the read-out signal is discussed. This effect is shown to modify the observed signal significantly. This may be relevant to recent experiments by Simmonds et al. ( Phys. Rev. Lett. 93 (2004) 077003).