English

Quantum One-Way Communication is Exponentially Stronger Than Classical Communication

Computational Complexity 2010-09-21 v1 Metric Geometry Quantum Physics

Abstract

In STOC 1999, Raz presented a (partial) function for which there is a quantum protocol communicating only O(logn)O(\log n) qubits, but for which any classical (randomized, bounded-error) protocol requires \poly(n)\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.

Cite

@article{arxiv.1009.3640,
  title  = {Quantum One-Way Communication is Exponentially Stronger Than Classical Communication},
  author = {Bo'az Klartag and Oded Regev},
  journal= {arXiv preprint arXiv:1009.3640},
  year   = {2010}
}
R2 v1 2026-06-21T16:15:51.090Z