8,190 research outputs found

    The one-way unlocalizable quantum discord

    Full text link
    In this paper, we present the concept of the one-way unlocalizable quantum discord and investigate its properties. We provide a polygamy inequality for it in tripartite pure quantum system of arbitrary dimension. Several tradeoff relations between the one-way unlocalizable quantum discord and other correlations are given. If the von Neumann measurement is on a part of the system, we give two expressions of the one-way unlocalizable quantum discord in terms of partial distillable entanglement and quantum disturbance. Finally, we also provide a lower bound for bipartite shareability of quantum correlation beyond entanglement in a tripartite system.Comment: 6 pages, 3 figures. Minor corrections, references adde

    High order magnon bound states in the quasi-one-dimensional antiferromagnet α\alpha-NaMnO2_2

    Full text link
    Here we report on the formation of two and three magnon bound states in the quasi-one-dimensional antiferromagnet α\alpha-NaMnO2_2, where the single-ion, uniaxial anisotropy inherent to the Mn3+^{3+} ions in this material provides a binding mechanism capable of stabilizing higher order magnon bound states. While such states have long remained elusive in studies of antiferromagnetic chains, neutron scattering data presented here demonstrate that higher order n>2n>2 composite magnons exist, and, specifically, that a weak three-magnon bound state is detected below the antiferromagnetic ordering transition of NaMnO2_2. We corroborate our findings with exact numerical simulations of a one-dimensional Heisenberg chain with easy-axis anisotropy using matrix-product state techniques, finding a good quantitative agreement with the experiment. These results establish α\alpha-NaMnO2_2 as a unique platform for exploring the dynamics of composite magnon states inherent to a classical antiferromagnetic spin chain with Ising-like single ion anisotropy.Comment: 5 pages, 4 figure

    The Dynamical Yang-Baxter Relation and the Minimal Representation of the Elliptic Quantum Group

    Full text link
    In this paper, we give the general forms of the minimal LL matrix (the elements of the LL-matrix are cc numbers) associated with the Boltzmann weights of the An−11A_{n-1}^1 interaction-round-a-face (IRF) model and the minimal representation of the An−1A_{n-1} series elliptic quantum group given by Felder and Varchenko. The explicit dependence of elements of LL-matrices on spectral parameter zz are given. They are of five different forms (A(1-4) and B). The algebra for the coefficients (which do not depend on zz) are given. The algebra of form A is proved to be trivial, while that of form B obey Yang-Baxter equation (YBE). We also give the PBW base and the centers for the algebra of form B.Comment: 23 page

    Null-stream veto for two co-located detectors: Implementation issues

    Full text link
    Time-series data from multiple gravitational wave (GW) detectors can be linearly combined to form a null-stream, in which all GW information will be cancelled out. This null-stream can be used to distinguish between actual GW triggers and spurious noise transients in a search for GW bursts using a network of detectors. The biggest source of error in the null-stream analysis comes from the fact that the detector data are not perfectly calibrated. In this paper, we present an implementation of the null-stream veto in the simplest network of two co-located detectors. The detectors are assumed to have calibration uncertainties and correlated noise components. We estimate the effect of calibration uncertainties in the null-stream veto analysis and propose a new formulation to overcome this. This new formulation is demonstrated by doing software injections in Gaussian noise.Comment: Minor changes; To appear in Class. Quantum Grav. (Proc. GWDAW10

    Quantized ionic conductance in nanopores

    Get PDF
    Ionic transport in nanopores is a fundamentally and technologically important problem in view of its occurrence in biological processes and its impact on novel DNA sequencing applications. Using microscopic calculations, here we show that ion transport may exhibit strong nonlinearities as a function of the pore radius reminiscent of the conductance quantization steps as a function of the transverse cross section of quantum point contacts. In the present case, however, conductance steps originate from the break up of the hydration layers that form around ions in aqueous solution. Once in the pore, the water molecules form wavelike structures due to multiple scattering at the surface of the pore walls and interference with the radial waves around the ion. We discuss these effects as well as the conditions under which the step-like features in the ionic conductance should be experimentally observable.Comment: 6 pages, 3 figures, updated to fix font

    Nanopore‐Based, Rapid Characterization of Individual Amyloid Particles in Solution: Concepts, Challenges, and Prospects

    Full text link
    Aggregates of misfolded proteins are associated with several devastating neurodegenerative diseases. These so‐called amyloids are therefore explored as biomarkers for the diagnosis of dementia and other disorders, as well as for monitoring disease progression and assessment of the efficacy of therapeutic interventions. Quantification and characterization of amyloids as biomarkers is particularly demanding because the same amyloid‐forming protein can exist in different states of assembly, ranging from nanometer‐sized monomers to micrometer‐long fibrils that interchange dynamically both in vivo and in samples from body fluids ex vivo. Soluble oligomeric amyloid aggregates, in particular, are associated with neurotoxic effects, and their molecular organization, size, and shape appear to determine their toxicity. This concept article proposes that the emerging field of nanopore‐based analytics on a single molecule and single aggregate level holds the potential to account for the heterogeneity of amyloid samples and to characterize these particles—rapidly, label‐free, and in aqueous solution—with regard to their size, shape, and abundance. The article describes the concept of nanopore‐based resistive pulse sensing, reviews previous work in amyloid analysis, and discusses limitations and challenges that will need to be overcome to realize the full potential of amyloid characterization on a single‐particle level.Information about amyloid aggregation states is critical to understanding the pathological progression of many neurodegenerative diseases. Resistive pulse‐based nanopore sensing is a unique single‐molecule approach to studying these aggregation states because it can determine information about individual amyloids, oligomeric species, or fibrils in an aqueous solution without fluorescent labels or chemical modifications.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146577/1/smll201802412_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146577/2/smll201802412.pd

    Flow reversals in thermally driven turbulence

    Get PDF
    We analyze the reversals of the large scale flow in Rayleigh-B\'enard convection both through particle image velocimetry flow visualization and direct numerical simulations (DNS) of the underlying Boussinesq equations in a (quasi) two-dimensional, rectangular geometry of aspect ratio 1. For medium Prandtl number there is a diagonal large scale convection roll and two smaller secondary rolls in the two remaining corners diagonally opposing each other. These corner flow rolls play a crucial role for the large scale wind reversal: They grow in kinetic energy and thus also in size thanks to plume detachments from the boundary layers up to the time that they take over the main, large scale diagonal flow, thus leading to reversal. Based on this mechanism we identify a typical time scale for the reversals. We map out the Rayleigh number vs Prandtl number phase space and find that the occurrence of reversals very sensitively depends on these parameters.Comment: 4 pages, 4 figure
    • 

    corecore