The multi-mode quantum Entropy Power Inequality
  The quantum version of a fundamental entropic data-processing inequality is presented. It establishes a lower bound for the entropy that can be generated in the output channels of a scattering process, which involves a collection of independent input bosonic modes (e.g., the modes of the electromagnetic field). The impact of this inequality in quantum information theory is potentially large and some relevant implications are considered in this work. 
Giacomo De Palma, Andrea Mari, Seth Lloyd, and Vittorio Giovannetti
quant-ph math-ph math.MP