Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Guided nucleation of superconductivity on a graded magnetic substrate   We demonstrate the controlled spatial nucleation of superconductivity in a
thin film deposited on periodic arrays of ferromagnetic dots with gradually
increasing diameter. The perpendicular magnetization of the dots induces
vortex-antivortex molecules in the sample, with the number of (anti)vortices
increasing with magnet size. The resulting gradient of antivortex density
between the dots predetermines local nucleation of superconductivity in the
sample as a function of the applied external field and temperature. In
addition, the compensation between the applied magnetic field and the
antivortices results in an unprecedented enhancement of the critical
temperature.

11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom