Protecting quantum information encoded in decoherence-free states against exchange errors

Daniel A. Lidar, David Bacon, Julia Kempe, K. Birgitta Whaley

Research output: Contribution to journalArticle


The exchange interaction between identical qubits in a quantum-information processor gives rise to unitary two-qubit errors. It is shown here that decoherence-free subspaces (DFSs) for collective decoherence undergo Pauli errors under exchange, which, however, do not take the decoherence-free states outside of the DFS. In order to protect DFSs against these errors it is sufficient to employ a recently proposed concatenated DFS quantum-error-correcting code scheme [D. A. Lidar, D. Bacon, and K.B. Whaley, Phys. Rev. Lett. 82, 4556 (1999)].

Original languageEnglish (US)
Article number052307
Pages (from-to)523071-523075
Number of pages5
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number5
StatePublished - May 2000


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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