English

A new inequality for the von Neumann entropy

Quantum Physics 2007-05-23 v1

Abstract

Strong subadditivity of von Neumann entropy, proved in 1973 by Lieb and Ruskai, is a cornerstone of quantum coding theory. All other known inequalities for entropies of quantum systems may be derived from it. Here we prove a new inequality for the von Neumann entropy which we prove is independent of strong subadditivity: it is an inequality which is true for any four party quantum state, provided that it satisfies three linear relations (constraints) on the entropies of certain reduced states.

Keywords

Cite

@article{arxiv.quant-ph/0406162,
  title  = {A new inequality for the von Neumann entropy},
  author = {Noah Linden and Andreas Winter},
  journal= {arXiv preprint arXiv:quant-ph/0406162},
  year   = {2007}
}

Comments

8 pages, 1 eps figure

R2 v1 2026-07-22T19:44:44.306Z