Universal Fault-Tolerant Computation on Decoherence-Free Subspaces
Abstract
A general scheme to perform universal quantum computation within decoherence-free subspaces (DFSs) of a system's Hilbert space is presented. This scheme leads to the first fault-tolerant realization of universal quantum computation on DFSs with the properties that (i) only one- and two-qubit interactions are required, and (ii) the system remains within the DFS throughout the entire implementation of a quantum gate. We show explicitly how to perform universal computation on clusters of the four-qubit DFS encoding one logical qubit each under "collective decoherence" (qubit-permutation-invariant system-bath coupling). Our results have immediate relevance to a number of solid-state quantum computer implementations, in particular those in which quantum logic is implemented through exchange interactions, such as the recently proposed spin-spin coupled GaAs quantum dot arrays and the Si:P nuclear spin arrays.
Cite
@article{arxiv.quant-ph/9909058,
title = {Universal Fault-Tolerant Computation on Decoherence-Free Subspaces},
author = {Dave Bacon and Julia Kempe and Daniel A. Lidar and K. B. Whaley},
journal= {arXiv preprint arXiv:quant-ph/9909058},
year = {2016}
}
Comments
5 pages, no figures. Many small changes and clarifications. Expanded discussion of relevance to solid-state implementations. This version to appear in Phys. Rev. Lett