Asymptotic quantum cloning is state estimation

The impossibility of perfect cloning and state estimation are two fundamental results in Quantum Mechanics. It has been conjectured that quantum cloning becomes equivalent to state estimation in the asymptotic regime where the number of clones tends to infinity. We prove this conjecture using two known results of Quantum Information Theory: the monogamy of quantum correlations and the properties of entanglement breaking channels.Comment: 4 pages, REVTE

Exosuit-induced improvements in walking after stroke: comprehensive analysis on gait energetics and biomechanics

Outstanding Poster Presentation Finalis

Secrecy content of two-qubit states

We analyze the set of two-qubit states from which a secret key can be extracted by single-copy measurements plus classical processing of the outcomes. We introduce a key distillation protocol and give the corresponding necessary and sufficient condition for positive key extraction. Our results imply that the critical error rate derived by Chau, Phys. Rev. A {\bf 66}, 060302 (2002), for a secure key distribution using the six-state scheme is tight. Remarkably, an optimal eavesdropping attack against this protocol does not require any coherent quantum operation.Comment: 5 pages, RevTe

High Energy Physics from High Performance Computing

We discuss Quantum Chromodynamics calculations using the lattice regulator. The theory of the strong force is a cornerstone of the Standard Model of particle physics. We present USQCD collaboration results obtained on Argonne National Lab's Intrepid supercomputer that deepen our understanding of these fundamental theories of Nature and provide critical support to frontier particle physics experiments and phenomenology.Comment: Proceedings of invited plenary talk given at SciDAC 2009, San Diego, June 14-18, 2009, on behalf of the USQCD collaboratio

Consistency of QTL for Dollar Spot Resistance Between Greenhouse and Field Inoculations, Multiple Locations, and Different Population Sizes in Creeping Bentgrass

Dollar spot caused by Sclerotinia homoeocarpa F. T. Bennett is the most economically important turf disease in North America. Previous work indicated differences among cultivars in their susceptibility to dollar spot (Bonos et al., 2003). Studies have indicated that dollar spot resistance might be quantitatively inherited (Bonos et al., 2003) but the number, location and effect of genomic regions conferring resistance is still not known. Therefore the objective of this research is to understand the effect of population size, inoculation assays, and field locations on QTL for dollar spot resistance in creeping bentgrass