Calculus of Variations and Geometric Measure Theory

Giacomo De Palma - D. Trevisan - V. Giovannetti

Passive states optimize the output of bosonic Gaussian quantum channels

created by trevisan on 10 Jun 2017



Inserted: 10 jun 2017

Year: 2015

ArXiv: 1511.00293 PDF


An ordering between the quantum states emerging from a single mode gauge-covariant bosonic Gaussian channel is proven. Specifically, we show that within the set of input density matrices with the same given spectrum, the element passive with respect to the Fock basis (i.e. diagonal with decreasing eigenvalues) produces an output which majorizes all the other outputs emerging from the same set. When applied to pure input states, our finding includes as a special case the result of A. Mari, et al., Nat. Comm. 5, 3826 (2014) which implies that the output associated to the vacuum majorizes the others.