Quantum+Speed+Limit

Here are the references related to the discussion we had on July 6th:
 * L. Levitin and T. Toffoli, arXiv:0905.3417
 * E.H. Lieb and D.W. Robinson, Commun. Math. Phys. **28**, 251 (1972)
 * S. Bravyi, M.B. Hastings, and F. Verstraete, PRL **97**, 050401 (2006)
 * J. Eisert, D. Gross, PRL **102**, 240501 (2009)
 * N. Khaneja, F. Kramer, S.J. Glaser, Journal of Magnetic Resonance **173**, 116 (2005)
 * T.O. Reiss, N. Khaneja, and S.J. Glaser, Journal of Magnetic Resonance **154**, 192 (2002)
 * N. Khaneja, R. Brockett, and S.J. Glaser, PRA **63**, 032308 (2001)
 * H. Yuan, S.J. Glaser, and N. Khaneja, PRA **76**, 012316 (2007)
 * H. Yuan, R. Zeier, and N. Khaneja, PRA **77**, 032340 (2008)
 * H. Yuan and N. Khaneja, PRA **72**, 040301 (2005)
 * R. Zeier, H. Yuan, and N. Khaneja, PRA **77**, 032332 (2008)
 * T. Caneva, M. Murphy, T. Calarco, R. Fazio, S. Montangero, V. Giovannetti, G.E. Santoro, arXiv:0902.4193