We investigate how to concatenate different decoherence-free subspaces (DFSs) to realize scalable universal fault-tolerant quantum computation. Based on tunable XXZ interactions, we present an architecture for scalable quantum computers which can fault-tolerantly perform universal quantum computation by manipulating only single type of parameter. By using the concept of interaction-free subspaces we eliminate the need to tune the couplings between logical qubits, which further reduces the technical difficulties for implementing quantum computation.
@article{arxiv.quant-ph/0407241,
title = {Scalable fault-tolerant quantum computation in DFS blocks},
author = {Zheng-Wei Zhou and Bo Yu and Xingxiang Zhou and Marc J. Feldman and Guang-Can Guo},
journal= {arXiv preprint arXiv:quant-ph/0407241},
year = {2009}
}