Efficient quantum filtering for quantum feedback control

Pierre Rouchon (1, 2) , Jason F Ralph (3)

1 CAS - Centre Automatique et Systèmes
2 QUANTIC - QUANTum Information Circuits
3 Department of Electrical Engineering and Electronics

We discuss an efficient numerical scheme for the recursive filtering of diffusive quantum stochastic master equations. We show that the resultant quantum trajectory is robust and may be used for feedback based on inefficient measurements. The proposed numerical scheme is amenable to approximation, which can be used to further reduce the computational burden associated with calculating quantum trajectories and may allow real-time quantum filtering. We provide a two-qubit example where feedback control of entanglement may be within the scope of current experimental systems.

Mots clés: quantum state-estimation; continuous weak measurement; quantum feedback control

Domaines: Sciences de l'ingénieur [physics]; Automatique / Robotique

Pierre Rouchon, Jason F Ralph. Efficient quantum filtering for quantum feedback control. Physical Review, 2015, 91, pp.012118. ⟨10.1103/PhysRevA.91.012118⟩. ⟨hal-01245070⟩