79,527 research outputs found
A reversible conversion between a skyrmion and a domain-wall pair in junction geometry
A skyrmion is a topological texture in the continuum field theory. Recent
experimental observation of skyrmions in chiral magnet evokes a flourish of its
extensive study. Skyrmion is expected to be a key component of the next
generation spintronics device called skyrmionics. On the other hand, there is a
well established memory device encoded by a sequence of domain walls. A
skyrmion carries a topological number, whereas a domain wall does not.
Nevertheless, we show a conversion is possible between a skyrmion and a
domain-wall pair by connecting wide and narrow nanowires, enabling the
information transmission between skyrmion device and domain-wall device. Our
results will be the basis of a hybrid device made of skyrmions and domain
walls, where the encoded information in domain walls is converted into
skyrmions, and then read out by converting the skyrmions back to domain walls
after a functional control of the skyrmions.Comment: 8 pages, 5 figure
Severe acute respiratory syndrome epidemic in Asia.
We analyzed the dynamics of cumulative severe acute respiratory syndrome (SARS) cases in Singapore, Hong Kong, and Beijing using the Richards model. The predicted total SARS incidence was close to the actual number of cases; the predicted cessation date was close to the lower limit of the 95% confidence interval
Hyperspherical Close-Coupling Calculation of D-wave Positronium Formation and Excitation Cross Sections in Positron-Hydrogen Scattering
Hyperspherical close-coupling method is used to calculate the elastic,
positronium formation and excitation cross sections for positron collisions
with atomic hydrogen at energies below the H(n=4) threshold for the J=2 partial
wave. The resonances below each inelastic threshold are also analyzed. The
adiabatic hyperspherical potential curves are used to identify the nature of
these resonances.Comment: 12 pages(in a TeX file) +8 Postscript figure
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