Information transmission under Markovian noise

Abstract

We consider an open quantum system undergoing Markovian dynamics, the latter being modelled by a discrete-time quantum Markov semigroup $({\Phi }^n{)}_{n\in \mathbb{N}}$, resulting from the action of sequential uses of a quantum channel $\Phi$, with $n\in \mathbb{N}$ being the discrete time parameter. We find upper and lower bounds on the one-shot $\epsilon$-error information transmission capacities of ${\Phi }^n$ for a finite time $n\in \mathbb{N}$ and $\epsilon \in [0,1)$ in terms of the structure of the peripheral space of the channel $\Phi$. We consider transmission of $(i)$ classical information (both in the unassisted and entanglement-assisted settings); $(ii)$ quantum information and $(iii)$ private classical information.

arXiv commentUpdated version. Finite time analysis has been slightly refined