Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Building traps for skyrmions by the incorporation of magnetic defects
  into nanomagnets: pinning and scattering traps by magnetic properties
  engineering   In this work we have used micromagnetic simulations to report four ways to
build traps for magnetic skyrmions. Magnetic defects have been modeled as local
variations in the material parameters, such as the exchange stiffness,
saturation magnetization, magnetocrystalline anisotropy and
Dzyaloshinskii-Moriya constant. We observe both pinning (potential well) and
scattering (potential barrier) traps when tuning either a local increase or a
local reduction for each one of these magnetic properties. It is found that the
skyrmion-defect aspect ratio is a crucial parameter to build traps for
skyrmions. In particular, the efficiency of the trap is compromised if the
defect size is smaller than the skyrmion size, because they interact weakly. On
the other hand, if the defect size is larger than the skyrmion diameter, the
skyrmion-defect interaction becomes evident. Thus, the strength of the
skyrmion-defect interaction can be tuned by the modification of the magnetic
properties within a region with suitable size. Furthermore, the basic physics
behind the mechanisms for pinning and for scattering is discussed. In
particular, we discover that skyrmions move towards the magnetic region which
tends to maximize its diameter; it enables the magnetic system to minimize its
energy. Thus, we are able to explain why skyrmions are either attracted or
repelled by a region with modified magnetic properties. Results here presented
are of utmost significance for the development and realization of future
spintronic devices, in which skyrmions will work as information carriers.

30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat