99%-fidelity ballistic quantum-state transfer through long uniform channels

TL;DR

This paper demonstrates that quantum states can be transferred with over 99% fidelity through long, uniform one-dimensional chains by tuning specific extremal bonds, applicable across various quantum models.

Contribution

It provides a universal framework for achieving high-fidelity quantum-state transfer in long uniform chains by tuning boundary interactions.

Findings

Achieves >99% fidelity in long chains

Identifies optimal boundary bond values for transfer

Applicable to fermion, boson, and spin models

Abstract

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 last-but-one). These have to be roughly tuned to suitable values x ~ 2 N^{-1/3} and y ~ 2^{3/4} N^{-1/6}, N being 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.