laboratoire pierre aigrain
électronique et photonique quantiques
laboratoire pierre aigrain

Séminaire 3 octobre 2011

Mazyar Mirrahimi (INRIA and Yale University)
Strong measurement and quantum feedback for persistent Rabi oscillations in circuit QED

In this talk, we will consider the stabilization of the dynamical state of a qubit. In a series of papers, A. Korotkov and his co-workers suggested that continuous weak measurement of the state of a qubit and applying an appropriate feedback on the amplitude of a Rabi drive, should allow us to maintain the coherence of the Rabi oscillations on an infinite horizon. Here, in the aim of approaching some realistic parameters of the circuit QED experiments, we study a new variant of such strategies based on performing strong measurements in a discrete-in-time manner and applying the measurement record to correct the phase of the Rabi oscillations.
Noting that, such persistent Rabi oscillations can be seen as an amplitude-to-frequency convertor (converting the amplitude of the Rabi drive to a precise frequency), we will propose another feedback layer (consisting of a simple analog loop) to compensate the low frequency deviations in the amplitude of the Rabi drive.