Restoring Quantum Coherence Pavia, Italy Decoherence remains the foremost limiting factor on practical implementation of quantum information technologies. In quant-ph 0504195, Buscemi et al. show that for qubit and qutrit systems it is always possible to recover quantum coherence by performing controlled measurements upon the environment, and that the minimal information required to invert qubit decoherence is equivalent to the von Neumann entropy exchange of the system.

Measuring Decoherence in a three-level rf SQUID Qubit U Kansas In cond-mat 0507008, Han et al. perform direct and quantitative measurements of dissipation-induced relaxation in a three-level rf SQUID qubit. "Analysis of the system indicates that the dominant sources of qubit dissipation are the flux bias and magnetometer readout circuits. Since this kind of dissipation-induced qubit decoherence can be greatly suppressed with more sophisticated designs we believe it does not impose a fundamental limit to this type of qubit [...] We are developing advanced designs for qubit bias and readout circuits that are predicted to decrease their contributions to the qubit damping by several orders of magnitude."

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