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Register a new userOn the distillation and purification of phase-diffused squeezed states
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Recently it was discovered that non-Gaussian decoherence processes, such as phase-diffusion, can be counteracted by purification and distillation protocols that are solely built on Gaussian operations. Here, we make use of this experimentally highly accessible regime, and provide a detailed experimental and theoretical analysis of several strategies for purification/distillation protocols on phase-diffused squeezed states. Our results provide valuable information for the optimization of such protocols with respect to the choice of the trigger quadrature, the trigger threshold value and the probability of generating a distilled state.
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We provide a detailed theoretical analysis of multiple copy purification and distillation protocols for phase diffused squeezed states of light. The standard iterative distillation protocol is generalized to a collective purification of an arbitrary number of N copies. We also derive a semi-analytical expression for the asymptotic limit of the iterative distillation and purification protocol and discuss its properties.
We show that a nonlinear asymmetric directional coupler composed of a linear waveguide and a nonlinear waveguide operating by nondegenerate parametric amplification is an effective source of single-mode squeezed light. This is has been demonstrated, under certain conditions and for specific modes, for incident coherent beams in terms of the quasiprobability functions, photon-number distribution and phase distribution.
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Photon subtraction from squeezed states is a powerful scheme to create good approximation of so-called Schrodinger cat states. However, conventional continuous-wave-based methods actually involve some impurity in squeezing of localized wavepackets, even in the ideal case of no optical losses. Here we theoretically discuss this impurity, by introducing mode-match of squeezing. Furthermore, here we propose a method to remove this impurity by filtering the photon-subtraction field. Our method in principle enables creation of pure photon-subtracted squeezed states, which was not possible with conventional methods.
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