Subadditivity of q-entropies for q>1
Mathematical Physics
2009-11-13 v1 math.MP
Quantum Physics
Abstract
I prove a basic inequality for Schatten q-norms of quantum states on a finite-dimensional bipartite Hilbert space H_1\otimes H_2: 1+||\rho||_q \ge ||\trace_1\rho||_q + ||\trace_2\rho||_q. This leads to a proof--in the finite dimensional case--of Raggio's conjecture (G.A. Raggio, J. Math. Phys.\ \textbf{36}, 4785--4791 (1995)) that the q-entropies S_q(\rho)=(1-\trace[\rho^q])/(q-1) are subadditive for q > 1; that is, for any state \rho, S_q(\rho) is not greater than the sum of the S_q of its reductions, S_q(\rho) \le S_q(\trace_1\rho)+S_q(\trace_2\rho).
Keywords
Cite
@article{arxiv.0705.1276,
title = {Subadditivity of q-entropies for q>1},
author = {Koenraad M. R. Audenaert},
journal= {arXiv preprint arXiv:0705.1276},
year = {2009}
}
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2 pages