A single-party strategy in a multi-round quantum protocol can be implemented by sequential networks of quantum operations connected by internal memories. Here provide the most efficient realization in terms of computational-space resources.
@article{arxiv.1006.1780,
title = {Minimal computational-space implementation of multi-round quantum protocols},
author = {A. Bisio and G. Chiribella and G. M. D'Ariano and P. Perinotti},
journal= {arXiv preprint arXiv:1006.1780},
year = {2011}
}