Quantum-State Transfer Through Disordered Hexagonal Lattices.

We investigate a quantum-state transfer protocol through a quasi-1D spin-1/2 channel defined on a hexagonal layer featuring hopping disorder. In the absence of disorder, the quantum channel displays two flat bands hosting compact localized states. That is signalled by the appearance of singularities in the density of states. We show that an arbitrary qubit state can be transmitted with high fidelity between the two ends even in the presence of noise as long as they are not in resonance with energy levels surrounding the flat band. This higher sensitivity against disorder is due to the residual single-cell compact localized states accompanied by a degeneracy lifting. [ABSTRACT FROM AUTHOR]