Quantum state transfer through a qubit network with energy shifts and fluctuations

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.