Quantum One-Way Communication is Exponentially Stronger Than Classical Communication

In STOC 1999, Raz presented a (partial) function for which there is a quantum protocol communicating only O(log n) qubits, but for which any classical (randomized, bounded-error) protocol requires poly(n) bits of communication. That quantum protocol requires two rounds of communication. Ever since Raz's paper it was open whether the same exponential separation can be achieved with a quantum protocol that uses only one round of communication. Here we settle this question in the affirmative.

• Type: Journal
• Year: 2010
• Where: CORR
• Authors: Bo'az Klartag, Oded Regev
• Keywords: Communication, CORR 2010, Education, Exponential Separation, Quantum Protocol