Contradiction of Quantum Mechanics with Local Hidden Variables for Continuous Variable Quadrature Phase Amplitude Measurements

摘要

We demonstrate a contradiction of quantum mechanics with local hiddenvariable theories for continuous variable quadrature phase amplitude(``position'' and ``momentum'') measurements, by way of a violation of a Bellinequality. For any quantum state, this contradiction is lost for situationswhere the quadrature phase amplitude results are always macroscopicallydistinct. We show that for optical realisations of this experiment, where oneuses homodyne detection techniques to perform the quadrature phase amplitudemeasurement, one has an amplification prior to detection, so that macroscopicfields are incident on photodiode detectors. The high efficiencies of suchdetectors may open a way for a loophole-free test of local hidden variabletheories.