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Multi-Party Pseudo-Telepathy

Gilles Brassard·Anne Broadbent·Alain Tapp
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Abstract

Quantum entanglement, perhaps the most non-classical manifestation of quantum information theory, cannot be used to transmit information between remote parties. Yet, it can be used to reduce the amount of communication required to process a variety of distributed computational tasks. We speak of pseudo-telepathy when quantum entanglement serves to eliminate the classical need to communicate. In earlier examples of pseudo-telepathy, classical protocols could succeed with high probability unless the inputs were very large. Here we present a simple multi-party distributed problem for which the inputs and outputs consist of a single bit per player, and we present a perfect quantum protocol for it. We prove that no classical protocol can succeed with a probability that differs from 1/2 by more than a fraction that is exponentially small in the number of players. This could be used to circumvent the detection loophole in experimental tests of nonlocality.

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Gilles Brassard, Anne Broadbent, Alain Tapp. 2003-06-05. Multi-Party Pseudo-Telepathy. https://doi.org/10.1007/978-3-540-45078-8_1

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