Dual-Path State Reconstruction Scheme for Propagating Quantum Microwaves and Detector Noise Tomography
E. P. Menzel, Frank Deppe, M. Mariantoni, Miguel Ángel Araque Caballero, A. Baust, Thomas M. Niemczyk, Eric A. Hoffmann, Achim Marx, E. Solano, R. Gross · Physical Review Letters · 2010
Quantum state reconstruction of weak propagating microwaves to date requires the use of linear amplifiers. We introduce a theory which, even in the presence of significant amplifier noise, allows one to use these devices for measuring all quadrature moments of propagating quantum microwaves based on cross correlations from a dual-path amplification setup. Simultaneously, the detector noise properties are determined, allowing for tomography. We demonstrate the feasibility of our novel concept by proof-of-principle experiments with classical mixtures of weak coherent microwaves.