Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measuring the magnetic moment density in patterned ultrathin
  ferromagnets with submicron resolution   We present a new approach to infer the surface density of magnetic moments
$I_s$ in ultrathin ferromagnetic films with perpendicular anisotropy. It relies
on quantitative stray field measurements with an atomic-size magnetometer based
on the nitrogen-vacancy center in diamond. The method is applied to
microstructures patterned in a 1-nm-thick film of CoFeB. We report measurements
of $I_s$ with a few percent uncertainty and a spatial resolution in the range
of $(100$ nm)$^2$, an improvement by several orders of magnitude over existing
methods. As an example of application, we measure the modifications of $I_s$
induced by local irradiation with He$^+$ ions in an ultrathin ferromagnetic
wire. This method offers a new route to study variations of magnetic properties
at the nanoscale.

30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat