Any quantum state can be cloned in the presence of closed timelike curves  "The possible existence of closed timelike curves (CTCs) draws attention to fundamental questions about what is physically possible and what is not. An example is the "no cloning theorem" in quantum mechanics — which states that no physical means exists by which an unknown arbitrary quantum state can be reproduced, or copied perfectly. We show here that this theorem can be circumvented in the presence of closed timelike curves, allowing for the cloning of an unknown arbitrary quantum state. Since the "no cloning theorem" has played a central role in the development of quantum information science, it is clear that the existence of CTCs would radically change the rules for quantum information technology." 
– Tim Ralph, David Ahn, R. B. Mann (arXiv:1008.0221)

Molecular Simulation with Superconducting Qubits 

"Because Nature isn't classical, damnit, and if you want to make a simulation of nature, you'd better make it quantum mechanical. " —Richard Feynman 

Georgia, UCSB In arXiv:1008.0701, Pritchett, Martinis et al. introduce a protocol for efficient simulation of molecular dynamics using superconducting qubits. "Recent experimental progress suggests that quantum simulation will be one of the first practical applications of quantum computation. We have shown how quantum computers of only a few qubits can simulate arbitrary quantum systems accurately and quickly, even before they reach the regime of fault tolerant quantum computation."

Decoherence sources in coupled flux qubits NEC, RIKEN In Phys Rev B and concurrent arXiv preprints, Yoshihara, Nakamura and Tsai study decoherence in coupled superconducting flux qubits. "The microscopic origin of decoherence has been elusive so far. It is crucial to identify and eliminate the source of noise sources in order to improve the performance of these devices—the sensitivity of SQUIDs and coherence of qubits. We have quantified the correlations among flux noise and found that the dominant contribution is by local fluctuations."

Superconducting qubits as artificial atoms

"The demonstrated resonance wave scattering indicates that superconducting quantum devices can be used as building blocks for controllable, quantum coherent, macroscopic artificial structures — in which a plethora of effects can be realized from quantum optics of atomic systems."

NEC 東京大学 This week's Qulink seminar by Yasunobu Nakamura (NEC) reports on recent developments in exploring the quantum optical properties of a superconducting flux qubit coupled to a 1d microwave transmission line. See also: Electromagnetically induced transparency on a single artificial atom (arXiv); Resonance fluorescence of a single artificial atom (Science); Ultimate on-chip quantum amplifier (Phys Rev Lett).