It is proved that a quantum computer with fixed and permanent interaction of diagonal type between qubits proposed in the work quant-ph/0201132 is universal. Such computer is controlled only by one-qubit quick transformations, and this makes it feasible.
@article{arxiv.quant-ph/0202030,
title = {Quantum Computer with Fixed Interaction is Universal},
author = {Yuri Ozhigov and Leonid Fedichkin},
journal= {arXiv preprint arXiv:quant-ph/0202030},
year = {2007}
}