1212.2354 (M. E. Shirokov)

On reversibility of Bosonic linear channels with respect to families of
pure states    [PDF]

M. E. Shirokov

Conditions for reversibility (sufficiency) of Bosonic linear channels (in particular, Bosonic Gaussian channels) with respect to families of pure states are studied. By noting first that non-ideal Bosonic linear channels are not reversible with respect to complete families of pure states, we focus attention on analysis of reversibility of such channels with respect to non-complete orthogonal and non-orthogonal families. By using the general reversibility condition expressed in terms of a complementary channel a characterization of reversibility properties of Bosonic linear channels is obtained and a description of reversed families of pure states in the Schrodinger representation is given. Reformulations of these results for Bosonic Gaussian channels and their physical interpretation are considered. Conditions for existence of discrete classical-quantum subchannels and of completely depolarizing subchannels of a Bosonic linear channel are obtained in the Appendix.

View original: http://arxiv.org/abs/1212.2354