2,124 research outputs found

    Adiabatic quantum computation along quasienergies

    Full text link
    The parametric deformations of quasienergies and eigenvectors of unitary operators are applied to the design of quantum adiabatic algorithms. The conventional, standard adiabatic quantum computation proceeds along eigenenergies of parameter-dependent Hamiltonians. By contrast, discrete adiabatic computation utilizes adiabatic passage along the quasienergies of parameter-dependent unitary operators. For example, such computation can be realized by a concatenation of parameterized quantum circuits, with an adiabatic though inevitably discrete change of the parameter. A design principle of adiabatic passage along quasienergy is recently proposed: Cheon's quasienergy and eigenspace anholonomies on unitary operators is available to realize anholonomic adiabatic algorithms [Tanaka and Miyamoto, Phys. Rev. Lett. 98, 160407 (2007)], which compose a nontrivial family of discrete adiabatic algorithms. It is straightforward to port a standard adiabatic algorithm to an anholonomic adiabatic one, except an introduction of a parameter |v>, which is available to adjust the gaps of the quasienergies to control the running time steps. In Grover's database search problem, the costs to prepare |v> for the qualitatively different, i.e., power or exponential, running time steps are shown to be qualitatively different. Curiously, in establishing the equivalence between the standard quantum computation based on the circuit model and the anholonomic adiabatic quantum computation model, it is shown that the cost for |v> to enlarge the gaps of the eigenvalue is qualitatively negligible.Comment: 11 pages, 2 figure

    Delay of Disorder by Diluted Polymers

    Full text link
    We study the effect of diluted flexible polymers on a disordered capillary wave state. The waves are generated at an interface of a dyed water sugar solution and a low viscous silicon oil. This allows for a quantitative measurement of the spatio-temporal Fourier spectrum. The primary pattern after the first bifurcation from the flat interface are squares. With increasing driving strength we observe a melting of the square pattern. It is replaced by a weak turbulent cascade. The addition of a small amount of polymers to the water layer does not affect the critical acceleration but shifts the disorder transition to higher driving strenghs and the short wave length - high frequency fluctuations are suppressed

    On vacuum gravitational collapse in nine dimensions

    Full text link
    We consider the vacuum gravitational collapse for cohomogeneity-two solutions of the nine dimensional Einstein equations. Using combined numerical and analytical methods we give evidence that within this model the Schwarzschild-Tangherlini black hole is asymptotically stable. In addition, we briefly discuss the critical behavior at the threshold of black hole formation.Comment: 4 pages, 4 figure

    Vacuum gravitational collapse in nine dimensions

    No full text
    We consider the vacuum gravitational collapse for cohomogeneity-two solutions of the nine dimensional Einstein equations. Using combined numerical and analytical methods we give evidence that within this model the Schwarzschild-Tangherlini black hole is asymptotically stable. In addition, we briefly discuss the critical behavior at the threshold of black-hole formation

    From simple to complex networks: inherent structures, barriers and valleys in the context of spin glasses

    Full text link
    Given discrete degrees of freedom (spins) on a graph interacting via an energy function, what can be said about the energy local minima and associated inherent structures? Using the lid algorithm in the context of a spin glass energy function, we investigate the properties of the energy landscape for a variety of graph topologies. First, we find that the multiplicity Ns of the inherent structures generically has a lognormal distribution. In addition, the large volume limit of ln/ differs from unity, except for the Sherrington-Kirkpatrick model. Second, we find simple scaling laws for the growth of the height of the energy barrier between the two degenerate ground states and the size of the associated valleys. For finite connectivity models, changing the topology of the underlying graph does not modify qualitatively the energy landscape, but at the quantitative level the models can differ substantially.Comment: 10 pages, 9 figs, slightly improved presentation, more references, accepted for publication in Phys Rev

    Cold Hardy Wine Grape Cultivar Trial

    Get PDF
    In conjunction with the Northeast Regional Research project NE 1020 “Multi-state Evaluation of Wine Grape Cultivars and Clones,” Iowa State University established a cold hardy wine grape cultivar trial in 2008 at the ISU Horticulture Research Station (HRS) and Tabor Home Vineyards and Winery (THV) near Baldwin, IA. The Iowa trial evaluates the performance of Corot noir, La Crescent, Marquette, Petit AmiTM, NY 95.0301-01, MN-1189, MN-1200, MN-1220, MN-1235, MN-1258 with Frontenac, and St. Croix serving as controls. This report summarizes the results for the 2012 growing season

    NE-1020 Cold Hardy Wine Grape Cultivar Trial

    Get PDF
    In conjunction with the Northeast Regional Research project NE-1020 “Multi-state Evaluation of Wine Grape Cultivars and Clones,” Iowa State University established a cold hardy wine grape cultivar trial in 2008 at the ISU Horticulture Research Station (HRS), Ames, Iowa, and Tabor Home Vineyards and Winery (THV), Baldwin, Iowa. The Iowa trial evaluates the performance of Corot noir, La Crescent, Marquette, Petit Ami™, NY95.0301- 01 (Arandell), MN1189, MN1200, MN1220, MN1235, MN1258, with Frontenac and St. Croix serving as controls. Selection NY95.0300-01 was shipped by mistake and was planted in the guard rows and as end-ofrow guard vines. This report summarizes the results for the 2013 growing season

    Gravitational waves from intermediate-mass-ratio inspirals for ground-based detectors

    Get PDF
    We explore the prospects for Advanced LIGO to detect gravitational waves from neutron stars and stellar mass black holes spiraling into intermediate-mass (M50MM\sim 50 M_\odot to 350M350 M_\odot) black holes. We estimate an event rate for such \emph{intermediate-mass-ratio inspirals} (IMRIs) of up to 10\sim 10--30yr130 \mathrm{yr}^{-1}. Our numerical simulations show that if the central body is not a black hole but its metric is stationary, axisymmetric, reflection symmetric and asymptotically flat then the waves will likely be tri-periodic, as for a black hole. We report generalizations of a theorem due to Ryan (1995) which suggest that the evolutions of the waves' three fundamental frequencies and of the complex amplitudes of their spectral components encode (in principle) a full map of the central body's metric, full details of the energy and angular momentum exchange between the central body and the orbit, and the time-evolving orbital elements. We estimate that Advanced LIGO can measure or constrain deviations of the central body from a Kerr black hole with modest but interesting accuracy.Comment: Accepted for publication in Physical Review Letter
    corecore