We study quantum state transfer through a qubit network modeled by spins with XY interaction, when relying on a single excitation. We show that it is possible to achieve perfect transfer by shifting (adding) energy to specific vertices. This technique appears to be a potentially powerful tool to change, and in some cases improve, transfer capabilities of quantum networks. Analytical results are presented for all-to-all networks and all-to-all networks with a missing link. Moreover, we evaluate the effect of random fluctuations on the transmission fidelity.
@article{arxiv.0904.4510,
title = {Quantum state transfer through a qubit network with energy shifts and fluctuations},
author = {Andrea Casaccino and Seth Lloyd and Stefano Mancini and Simone Severini},
journal= {arXiv preprint arXiv:0904.4510},
year = {2010}
}