A New Inequality for the von Neumann Entropy
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.
- Publication:
-
Communications in Mathematical Physics
- Pub Date:
- October 2005
- DOI:
- 10.1007/s00220-005-1361-2
- arXiv:
- arXiv:quant-ph/0406162
- Bibcode:
- 2005CMaPh.259..129L
- Keywords:
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- Quantum Physics
- E-Print:
- 8 pages, 1 eps figure