We study the quantum state transfer (QST) in a class of qubit network with on-site interaction, which is described by the generalized Hubbard model with engineered couplings. It is proved that the system of two electrons with opposite spins in this quantum network of N sites can be rigorously reduced into N one dimensional engineered single Bloch electron models with central potential barrier. With this observation we find that such system can perform a perfect QST, the quantum swapping between two distant electrons with opposite spins. Numerical results show such QST and the resonant-tunnelling for the optimal on-site interaction strengths.
@article{arxiv.quant-ph/0510109,
title = {Quantum state swapping via qubit network with Hubbard interaction},
author = {S. Yang and Z. Song and C. P. Sun},
journal= {arXiv preprint arXiv:quant-ph/0510109},
year = {2011}
}