We propose and analyse a robust quantum state transfer protocol by the use of a combination of coherent quantum coupling and decoherence-free subspaces in a coupled quantum spin chain. Under decoherence, an arbitrary unknown quantum state embedded in a decoherence-free subspace can be perfectly transferred through a noisy channel being weakly coupled to two end registers. The method protects quantum information from both the channel noise and the environmental decoherence. A special case of utilizing two physical qubits to encode one logical qubit is considered as an example and the robustness is confirmed by numerical performances.
@article{arxiv.1503.08617,
title = {Protected quantum-state transfer in decoherence-free subspaces},
author = {Wei Qin and Chuan Wang and Xiangdong Zhang},
journal= {arXiv preprint arXiv:1503.08617},
year = {2015}
}