



01741nas a2200205   4500008004100000245007000041210006900111260001500180490000600195520112800201100001901329700002001348700001301368700002401381700002201405700002301427700002301450700002501473856003701498       2019                        eng d00aLocality and digital quantum simulation of power-law interactions0 aLocality and digital quantum simulation of powerlaw interactions  c07/10/20190 v93 a<p>The propagation of information in non-relativistic quantum systems obeys a speed limit known as a Lieb-Robinson bound. We derive a new Lieb-Robinson bound for systems with interactions that decay with distance r as a power law, 1/rα. The bound implies an effective light cone tighter than all previous bounds. Our approach is based on a technique for approximating the time evolution of a system, which was first introduced as part of a quantum simulation algorithm by Haah et al. [arXiv:1801.03922]. To bound the error of the approximation, we use a known Lieb-Robinson bound that is weaker than the bound we establish. This result brings the analysis full circle, suggesting a deep connection between Lieb-Robinson bounds and digital quantum simulation. In addition to the new Lieb-Robinson bound, our analysis also gives an error bound for the Haah et al. quantum simulation algorithm when used to simulate power-law decaying interactions. In particular, we show that the gate count of the algorithm scales with the system size better than existing algorithms when α&gt;3D (where D is the number of dimensions).</p>1 aTran, Minh, C.1 aGuo, Andrew, Y.1 aSu, Yuan1 aGarrison, James, R.1 aEldredge, Zachary1 aFoss-Feig, Michael1 aChilds, Andrew, M.1 aGorshkov, Alexey, V.  uhttps://arxiv.org/abs/1808.0522501519nas a2200217   4500008004100000245008300041210006900124260001400193490000800207520087700215100002001092700002101112700002201133700001201155700002101167700002301188700002001211700002101231700001201252856003701264       2012                        eng d00aLong-lived dipolar molecules and Feshbach molecules in a 3D optical  lattice
0 aLonglived dipolar molecules and Feshbach molecules in a 3D optic  c2012/2/230 v1083 a  We have realized long-lived ground-state polar molecules in a 3D optical
lattice, with a lifetime of up to 25 s, which is limited only by off-resonant
scattering of the trapping light. Starting from a 2D optical lattice, we
observe that the lifetime increases dramatically as a small lattice potential
is added along the tube-shaped lattice traps. The 3D optical lattice also
dramatically increases the lifetime for weakly bound Feshbach molecules. For a
pure gas of Feshbach molecules, we observe a lifetime of >20 s in a 3D optical
lattice; this represents a 100-fold improvement over previous results. This
lifetime is also limited by off-resonant scattering, the rate of which is
related to the size of the Feshbach molecule. Individually trapped Feshbach
molecules in the 3D lattice can be converted to pairs of K and Rb atoms and
back with nearly 100% efficiency.
1 aChotia, Amodsen1 aNeyenhuis, Brian1 aMoses, Steven, A.1 aYan, Bo1 aCovey, Jacob, P.1 aFoss-Feig, Michael1 aRey, Ana, Maria1 aJin, Deborah, S.1 aYe, Jun  uhttp://arxiv.org/abs/1110.4420v1