Capacities of Quantum Channels for Massive Bosons and Fermions

Abstract

We consider the capacity of classical information transfer for noiseless quantum channels carrying a finite average number of massive bosons and fermions. The maximum capacity is attained by transferring the Fock states generated from the grand-canonical ensemble. Interestingly, the channel capacity for a Bose gas indicates the onset of a Bose-Einstein condensation, by changing its qualitative behavior at the criticality, while for a channel carrying weakly attractive fermions, it exhibits the signatures of Bardeen-Cooper-Schrieffer transition. We also show that for noninteracting particles, fermions are better carriers of information than bosons.

4 pages, 3 eps figures, RevTeX4; v2: discussions added, small changes, published version