2N qubit “mirror states” for optimal quantum communicationS. Muralidharan, S. Karumanchi, S. Jain, R. Srikanth and P. K. PanigrahiEur. Phys. J. D, 61 3 (2011) 757-763DOI: https://doi.org/10.1140/epjd/e2010-09653-x