On Density Operators with Gaussian Weyl Symbols
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The notion of reduced density operator plays a fundamental role in quantum mechanics where it is used as a tool to study statistical properties of subsystems. In the present work we review this notion rigorously from a mathematical perspective using pseudodifferential theory, and we give a new necessary and sufficient condition for a Gaussian density operator to be separable.
This work has been financed by the Austrian Research Foundation FWF (Grant number P27773). It is our pleasure to thank a Referee for very useful remarks and for having pointed out inaccuracies in a first version of this work.
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