We present a feedback scheme to produce quantum non-Gaussian states from linear optical elements. Instead of traditional additive control methods, we introduce a mutiplicative feedback control and apply it to the deterministic generation of quantum superposition states. The protocol of feedback control is based on quantum nondemolition measurement of a quadrature, multifeedback structure, and Lyapunov stability for feedback design.

• Received 1 April 2009

DOI:https://doi.org/10.1103/PhysRevLett.103.203601