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arXiv · 1702.02550

Time-dependent quantum correlations in phase space

Fabian Krumm·Werner Vogel·Jan Sperling
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Abstract

General quasi-probabilities are introduced to visualize time-dependent quantum correlations of light in phase space. They are based on the generalization of the Glauber-Sudarshan P function to a time-dependent P functional [W. Vogel, Phys. Rev. Lett. 100, 013605 (2008)], which fully describes temporal correlations of radiation fields on the basis of continuous phase-space distributions. This approach is nontrivial as the P functional itself is highly singular for many quantum states and nonlinear processes. In general, it neither yields a well-behaved nor an experimentally accessible description of quantum stochastic processes. Our regularized version of this multi-time-dependent quasi-probability is a smooth function and applies to stronger divergences compared to the single-time and multi-mode scenario. The technique is used to characterize an optical parametric process with frequency mismatch. A measurement scheme, together with a sampling approach, is provided which yields direct experimental access to the regularized P functional from measured data.

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Fabian Krumm, Werner Vogel, Jan Sperling. 2017-06-09. Time-dependent quantum correlations in phase space. https://doi.org/10.1103/physreva.95.063805

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