Noise-resilient quantum interface based on quantum nondemolition interactions

We propose a quantum interface protocol based on two quantum nondemolition (QND) interactions arranged either in sequence or in parallel. Since the QND coupling arises naturally in interactions between light and a macroscopic ensemble of atoms, or between light and a micromechanical oscillator, the proposed interface is capable of transferring a state of light onto these matter systems. The transfer itself is perfect and deterministic for any quantum state, for arbitrarily small interaction strengths, and for arbitrarily large noise of the target system. It requires an all-optical preprocessing with a coupling stronger than that between the light and the matter, and a displacement feed-forward correction of the matter system. We also suggest a probabilistic version of the interface, which eliminates the need for the feed-forward correction at the cost of a reduced success rate. An application of the interface can be found in the construction of a quantum memory or in the state preparation for quantum sensing.