DIMACS Theoretical Computer Science Seminar

Title: Quantum One-Way Communication can be Exponentially Stronger Than Classical Communication

Speaker: Oded Regev, Courant Institute, NYU

Date: Wednesday, April 17, 2013 11:00-12:00pm

Location: DIMACS Center, CoRE Bldg, Room 431, Rutgers University, Busch Campus, Piscataway, NJ


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 $n^\eps$ 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. In other words, can quantum one-way communication be exponentially stronger than classical two-way communication? Here we settle this question in the affirmative.

The talk is entirely self-contained. In particular, there is no need to be familiar with quantum communication (since it barely shows up in our proof).

Based on joint work with Bo'az Klartag.

See: http://paul.rutgers.edu/~yixinxu/theory-spring13.html