8,190 research outputs found
The one-way unlocalizable quantum discord
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 -NaMnO
Here we report on the formation of two and three magnon bound states in the
quasi-one-dimensional antiferromagnet -NaMnO, where the single-ion,
uniaxial anisotropy inherent to the Mn 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
composite magnons exist, and, specifically, that a weak three-magnon
bound state is detected below the antiferromagnetic ordering transition of
NaMnO. 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 -NaMnO 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
In this paper, we give the general forms of the minimal matrix (the
elements of the -matrix are numbers) associated with the Boltzmann
weights of the interaction-round-a-face (IRF) model and the minimal
representation of the series elliptic quantum group given by Felder
and Varchenko. The explicit dependence of elements of -matrices on spectral
parameter are given. They are of five different forms (A(1-4) and B). The
algebra for the coefficients (which do not depend on ) 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
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
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
NanoporeâBased, Rapid Characterization of Individual Amyloid Particles in Solution: Concepts, Challenges, and Prospects
Aggregates of misfolded proteins are associated with several devastating neurodegenerative diseases. These soâcalled 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 amyloidâforming protein can exist in different states of assembly, ranging from nanometerâsized monomers to micrometerâlong 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 nanoporeâbased analytics on a single molecule and single aggregate level holds the potential to account for the heterogeneity of amyloid samples and to characterize these particlesârapidly, labelâfree, and in aqueous solutionâwith regard to their size, shape, and abundance. The article describes the concept of nanoporeâbased 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 singleâparticle level.Information about amyloid aggregation states is critical to understanding the pathological progression of many neurodegenerative diseases. Resistive pulseâbased nanopore sensing is a unique singleâmolecule 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
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
- âŠ