99 % -fidelity ballistic quantum-state transfer through long uniform channels
Tony J. G. Apollaro, Leonardo Banchi, Alessandro Cuccoli, Ruggero Vaia, Paola Verrucchi · Physical Review A · 2012
Quantum-state transfer with fidelity higher than $0.99$ can be achieved in the ballistic regime of an arbitrarily long one-dimensional chain with uniform nearest-neighbor interaction, except for the two pairs of mirror-symmetric extremal bonds, say $x$ (first and last) and $y$ (second and penultimate). These have to be roughly tuned to suitable values $x\ensuremath{\sim}2{N}^{\ensuremath{-}1/3}$ and $y\ensuremath{\sim}{2}^{3/4}{N}^{\ensuremath{-}1/6}$, where $N$ is the chain length. The general framework can describe the end-to-end response in different models, such as fermion or boson hopping models and $XX$ spin chains.