1 Department of Physics and Astronomy, Science and Technology, Aarhus University2 Tel-Aviv University3 unknown4 Department of Physics and Astronomy, Science and Technology, Aarhus University
We present a new robust decoupling scheme suitable for half integer angular momentum states. The scheme is based on continuous dynamical decoupling techniques by which we create a protected qubit subspace. Our scheme predicts a coherence time of ~1 second, as compared to typically a few milliseconds for the bare states. We show how single qubit gates and an ensemble coupling to a cavity mode can be implemented efficiently. Our scheme can be realized with state-of-the-art experimental setups and thus has immediate applications for quantum information science, and in particular for systems of rare-earth ions in crystals, and trapped alkaline earth ions.