Quantum Information with Optical Continuous Variables

Braunstein, Samuel, Pati, Arun

Kuanshou Zhang, Jinxia Feng, Yuanji Li

Metropolitan fiber quantum communication network is the key step to construct quantum communication network. Owing to continuous variable (CV) quantum entangled states of optical field can be generated unconditionally and deterministically, high-performance quantum information processing with continuous variables based on quantum states of optical field can be achieved. However, quantum information processing with continuous variable over optical fiber is a great challenge.

Nicolas J. Cerf

Patrick M. Hayden, Sepehr Nezami, Grant Salton +1 more

The theory of relativity requires that no information travel faster than light, whereas the unitarity of quantum mechanics ensures that quantum information cannot be cloned. These conditions provide the basic constraints that appear in information replication tasks, which formalize aspects of the behavior of information in relativistic quantum mechanics. In this article, we provide continuous variable (CV) strategies for spacetime quantum information replication that are directly amenable to optical or mechanical implementation. We use a new class of homologically constructed CV quantum error correcting codes to provide efficient solutions for the general case of information replication. As compared to schemes encoding qubits, our CV solution requires half as many shares per encoded system. We also provide an optimized five-mode strategy for replicating quantum information in a particular configuration of four spacetime regions designed not to be reducible to previously performed experiments. For this optimized strategy, we provide detailed encoding and decoding procedures using standard optical apparatus and calculate the recovery fidelity when finite squeezing is used. As such we provide a scheme for experimentally realizing quantum information replication using quantum optics.

Philippe Grangier

Kuanshou Zhang

The preparation of Continuous Variable(CV) squeezed light plays a key role in quantum optics and quantum information.Particularly,multimode squeezed light in CV have great potential application in quantum communication,quantum commutation and high precision measurement.In the review,we describe the research progress in this area,with focus on CV multimode squeezed state.