Fidelity criterion for quantum-domain transmission and storage of coherent states beyond unit-gain constraint

Date/Time: 24 January 2008 / 16:30- - ()

Speaker: Dr. Ryo Namiki (Osaka University)

If a quantum channel or process cannot be described by any measure-and-prepare scheme, we may say the channel is in quantum domain(QD) since it can transmit quantum correlations. The concept of QD clarifies the role of quantum channel in quantum information theory based on the local-operation-and-classical-communication (LOCC) paradigm: The quantum channel is only useful if it cannot be simulated by LOCC. We present a verification scheme of QD channel for continuous variable quantum channels based on measured fidelities assuming the input of coherent states with a Gaussian prior probability distribution.