New paper! New paper! Let’s all do the new paper dance. Posted to the arxiv today: quant-ph 0503047. This paper is a revision of an earlier paper, where now it is shown that the protocol in the earlier paper is in fact optimal.
Optimal classical-communication-assisted local model of n-qubit Greenberger-Horne-Zeilinger correlations
Authors: Tracey E. Tessier, Carlton M. Caves, Ivan H. Deutsch, Dave Bacon, Bryan Eastin
Comments: This submission supersedes quant-ph/0407133. It is a substantially revised version of the previous document and now includes an optimality proof of our model
We present a model, motivated by the criterion of reality put forward by Einstein, Podolsky, and Rosen and supplemented by classical communication, which correctly reproduces the quantum-mechanical predictions for measurements of all products of Pauli operators on an n-qubit GHZ state (or "cat state"). The n-2 bits employed by our model is shown to be optimal for the allowed set of measurements, demonstrating that the required communication overhead scales linearly with n. We formulate a connection between the generation of the local values utilized by our model and the stabilizer formalism, which leads us to conjecture that a generalization of this method will shed light on the content of the Gottesman-Knill theorem.
Nothing should feel better, I guess…