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What is entanglement?

Emilio Santos
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Abstract

I conjecture that only those states of light whose Wigner function is positive are real states, and give arguments suggesting that this is not a serious restriction. Hence it follows that the Wigner formalism in quantum optics is capable of interpretation as a classical wave field with the addition of a zeropoint contribution. Thus entanglement between pairs of photons with a common origin occurs because the two light signals have amplitudes and phases, both below and above the zeropoint intensity level, which are correlated with each other.

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Emilio Santos. 2002-04-04. What is entanglement?. https://arxiv.org/abs/quant-ph/0204020

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