1,846 research outputs found
Lambda and Anti-Lambda Hypernuclei in Relativistic Mean-field Theory
Several aspects about -hypernuclei in the relativistic mean field
theory, including the effective -nucleon coupling strengths based on
the successful effective nucleon-nucleon interaction PK1, hypernuclear magnetic
moment and -hypernuclei, have been presented. The effect of tensor
coupling in -hypernuclei and the impurity effect of to
nuclear structure have been discussed in detail.Comment: 8 pages, 2 figures, Proceedings of the Sendai International Symposium
"Strangeness in Nuclear and Hadronic Systems SENDAI08
A two-phase tabu-evolutionary algorithm for the 0–1 multidimensional knapsack problem
The 0–1 multidimensional knapsack problem is a well-known NP-hard combinatorial optimization problem with numerous applications. In this work, we present an effective two-phase tabu-evolutionary algorithm for solving this computationally challenging problem. The proposed algorithm integrates two solution-based tabu search methods into the evolutionary framework that applies a hyperplane-constrained crossover operator to generate offspring solutions, a dynamic method to determine search zones of interest, and a diversity-based population updating rule to maintain a healthy population. We show the competitiveness of the proposed algorithm by presenting computational results on the 281 benchmark instances commonly used in the literature. In particular, in a computational comparison with the best algorithms in the literature on multiple data sets, we show that our method on average matches more than twice the number of best known solutions to the harder problems than any other method and in addition yields improved best solutions (new lower bounds) for 4 difficult instances. We investigate two key ingredients of the algorithm to understand their impact on the performance of the algorithm
Kondo correlation and spin-flip scattering in spin-dependent transport through a quantum dot coupled to ferromagnetic leads
We investigate the linear and nonlinear dc transport through an interacting
quantum dot connected to two ferromagnetic electrodes around Kondo regime with
spin-flip scattering in the dot. Using a slave-boson mean field approach for
the Anderson Hamiltonian having finite on-site Coulomb repulsion, we find that
a spin-flip scattering always depresses the Kondo correlation at arbitrary
polarization strength in both parallel and antiparallel alignment of the lead
magnetization and that it effectively reinforces the tunneling related
conductance in the antiparallel configuration. For systems deep in the Kondo
regime, the zero-bias single Kondo peak in the differential conductance is
split into two peaks by the intradot spin-flip scattering; while for systems
somewhat further from the Kondo center, the spin-flip process in the dot may
turn the zero-bias anomaly into a three-peak structure.Comment: 4 pages, 2 figure
Magnetic-field induced resistivity minimum with in-plane linear magnetoresistance of the Fermi liquid in SrTiO3-x single crystals
We report novel magnetotransport properties of the low temperature Fermi
liquid in SrTiO3-x single crystals. The classical limit dominates the
magnetotransport properties for a magnetic field perpendicular to the sample
surface and consequently a magnetic-field induced resistivity minimum emerges.
While for the field applied in plane and normal to the current, the linear
magnetoresistance (MR) starting from small fields (< 0.5 T) appears. The large
anisotropy in the transverse MRs reveals the strong surface interlayer
scattering due to the large gradient of oxygen vacancy concentration from the
surface to the interior of SrTiO3-x single crystals. Moreover, the linear MR in
our case was likely due to the inhomogeneity of oxygen vacancies and oxygen
vacancy clusters, which could provide experimental evidences for the unusual
quantum linear MR proposed by Abrikosov [A. A. Abrikosov, Phys. Rev. B 58, 2788
(1998)].Comment: 5 pages, 4 figure
A learning-based path relinking algorithm for the bandwidth coloring problem
This paper proposes a learning-based path relinking algorithm (LPR) for solving the bandwidth coloring problem and the bandwidth multicoloring problem. Based on the population path-relinking framework, the proposed algorithm integrates a learning-driven tabu optimization procedure and a path-relinking operator. LPR is assessed on two sets of 66 common benchmark instances, and achieves highly competitive results in terms of both solution quality and computational efficiency compared to the state-of-the-art algorithms in the literature. Specifically, the algorithm establishes 7 new upper bounds while matching the best known results for 56 cases. The impacts of the learning mechanism and the path relinking operators are investigated, confirming their critical role to the success of the proposed algorithm
Nonorthogonal decoy-state Quantum Key Distribution
In practical quantum key distribution (QKD), weak coherent states as the
photon sources have a limit in secure key rate and transmission distance
because of the existence of multiphoton pulses and heavy loss in transmission
line. Decoy states method and nonorthogonal encoding protocol are two important
weapons to combat these effects. Here, we combine these two methods and propose
a efficient method that can substantially improve the performance of QKD. We
find a 79 km increase in transmission distance over the prior record using
decoy states method.Comment: 4 pages, 1 figure; Revtex4, submitted to PR
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