title: Decoherence by correlated noise and quantum error correction.
abstract: We study the decoherence of a quantum computer in an environment which is inherently correlated in time and space. We first derive the nonunitary time evolution of the computer and environment in the presence of a stabilizer error correction code, providing a general way to quantify decoherence for a quantum computer. The general theory is then applied to the spin-boson model. Our results demonstrate that effects of long-range correlations can be systematically reduced by small changes in the error correction codes.
authors.affiliation: Department of Physics, Duke University, Durham, North Carolina 27708-0305, USA.
authors.forename: E
authors.initials: E
authors.lastname: Novais
authors.forename: Harold U
authors.initials: HU
authors.lastname: Baranger