English

A new exponential separation between quantum and classical one-way communication complexity

Quantum Physics 2012-08-02 v3 Computational Complexity

Abstract

We present a new example of a partial boolean function whose one-way quantum communication complexity is exponentially lower than its one-way classical communication complexity. The problem is a natural generalisation of the previously studied Subgroup Membership problem: Alice receives a bit string x, Bob receives a permutation matrix M, and their task is to determine whether Mx=x or Mx is far from x. The proof uses Fourier analysis and an inequality of Kahn, Kalai and Linial.

Cite

@article{arxiv.1007.3587,
  title  = {A new exponential separation between quantum and classical one-way communication complexity},
  author = {Ashley Montanaro},
  journal= {arXiv preprint arXiv:1007.3587},
  year   = {2012}
}

Comments

19 pages; v3: improved results and some bug fixes

R2 v1 2026-06-21T15:50:49.193Z