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J. Mizuno

Publications and source records attributed to J. Mizuno.

3 recordsLinked to original sources

EPR Beams and Photon Number Detector: Toward Synthesizing Optical Nonlinearity

We present the two kinds of experimental results. One is a continuous variable dense coding experiment, and the other is a photon number detector with high linearity response, the so called charge integration photon detector (CIPD). They can be combined together to be a potential tool for implementing the cubic phase gate which is an important gate element to synthesize the measurement induced nonlinearity for photonic quantum information processing.

quant-ph

Implementation of generalized quantum measurements: superadditive quantum coding, accessible information extraction, and classical capacity limit

Quantum information theory predicts that when the transmission resource is doubled in quantum channels, the amount of information transmitted can be increased more than twice by quantum channel coding technique, whereas the increase is at most twice in classical information theory. This remarkable feature, the superadditive quantum coding gain, can be implemented by appropriate choices of code words and corresponding quantum decoding which requires a collective quantum measurement. Recently, the first experimental demonstration was reported [Phys. Rev. Lett. 90, 167906 (2003)]. The purpose of this paper is to describe our experiment in detail. Particularly, a design strategy of quantum collective decoding in physical quantum circuits is emphasized. We also address the practical implication of the gain on communication performance by introducing the quantum-classical hybrid coding scheme. We show how the superadditive quantum coding gain, even in a small code length, can boost the communication performance of conventional coding technique.

quant-ph

Demonstration of detuned dual recycling at the Garching 30m laser interferometer

Dual recycling is an advanced optical technique to enhance the signal-to-noise ratio of laser interferometric gravitational wave detectors in a limited bandwidth. To optimise the center of this band with respect to Fourier frequencies of expected gravitational wave signals detuned dual recycling has to be implemented. We demonstrated detuned dual recycling on a fully suspended 30m prototype interferometer. A control scheme that allows to tune the detector to different frequencies will be outlined. Good agreement between the experimental results and numerical simulations has been achieved.

gr-qc