Grover search in decoherence-free subspace with low-Q cavities

By virtue of the single-photon input-output process, we present a potentially practical scheme for realization of a multi- qubitGrover search algorithmin decoherence-free subspace(DFS) with low-Q cavities. Our treatment considers the decay of the cavity, which favours the input and output of the single photons, and the DFS encoding suppresses the collective dephasingerrors. We show that our scheme for the three- qubitGrover search in DFS would work using near-future available techniques.