title: Monte Carlo simulation of a noisy quantum channel with memory.
abstract: The classical capacity of quantum channels is well understood for channels with uncorrelated noise. For the case of correlated noise, however, there are still open questions. We calculate the classical capacity of a forgetful channel constructed by Markov switching between two depolarizing channels. Techniques have previously been applied to approximate the output entropy of this channel and thus its capacity. In this paper, we use a Metropolis-Hastings Monte Carlo approach to numerically calculate the entropy. The algorithm is implemented in parallel and its performance is studied and optimized. The effects of memory on the capacity are explored and previous results are confirmed to higher precision.
authors.affiliation: Department of Pure and Applied Mathematics, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2092, South Africa.
authors.forename: Ismail
authors.initials: I
authors.lastname: Akhalwaya
authors.affiliation: School of Physics, Quantum Research Group, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa.
authors.forename: Mervlyn
authors.initials: M
authors.lastname: Moodley
authors.affiliation: School of Physics, Quantum Research Group, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa.|National Institute for Theoretical Physics (NITheP), KwaZulu-Natal, South Africa.
authors.forename: Francesco
authors.initials: F
authors.lastname: Petruccione