16,818 research outputs found
Engineering planar transverse domain walls in biaxial magnetic nanostrips by tailoring transverse magnetic fields with uniform orientation
Designing and realizing various magnetization textures in magnetic
nanostructures are essential for developing novel magnetic nanodevices in
modern information industry. Among all these textures, planar transverse domain
walls (pTDWs) are the simplest and the most basic, which make them popular in
device physics. In this work, we report the engineering of pTDWs with arbitrary
tilting attitude in biaxial magnetic nanostrips by transverse magnetic field
profiles with uniform orientation but tunable strength distribution. Both
statics and axial-field-driven dynamics of these pTDWs are analytically
investigated. It turns out that for statics these pTDWs are robust again
disturbances which are not too abrupt, while for dynamics it can be tailored to
acquire higher velocity than Walker's ansatz predicts. These results should
provide inspirations for designing magnetic nanodevices with novel
one-dimensional magnetization textures, such as 360 walls, or even
two-dimensional ones, for example vortices, skyrmions, etc.Comment: 14 pages, 3 figure
Applications of degree estimate for subalgebras
Let be a field of positive characteristic and be the free
algebra of rank two over . Based on the degree estimate done by Y.-C. Li and
J.-T. Yu, we extend the results of S.J. Gong and J.T. Yu's results: (1) An
element is a test element if and only if does not
belong to any proper retract of ; (2) Every endomorphism preserving the
automorphic orbit of a nonconstant element of is an automorphism; (3)
If there exists some injective endomorphism of such that
where , then is a coordinate. And
we reprove that all the automorphisms of are tame. Moreover, we also
give counterexamples for two conjectures established by Leonid Makar-Limanov,
V. Drensky and J.-T. Yu in the positive characteristic case.Comment: 12 page
Search for charmonium and XYZ states in at BESIII
Within the framework of nonrelativistic quantum chromodynamics, we study the
production of charmonium states in at BESIII
with (n=1, 2, 3, and 4), (n=1, 2, and 3), and
(n=1 and 2). The radiative and relativistic corrections are
calculated to next-to-leading order for and wave states. We then argue
that the search for states such as , , ,
and in at BESIII may help clarify the nature
of these states. BESIII can search states through two body process
, where decay to , , or
. This result may be useful in identifying the nature of
states. For completeness, the production of charmonium in at B factories is also discussed.Comment: Comments and suggestions are welcome. References are update
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