Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Direct measurements of the penetration depth in a superconducting film
  using magnetic force microscopy   We report the local measurements of the magnetic penetration depth $\lambda$
in a superconducting Nb film using magnetic force microscopy (MFM). We
developed a method for quantitative extraction of the penetration depth from
single-parameter simultaneous fits to the lateral and height profiles of the
MFM signal, and demonstrate that the obtained value is in excellent agreement
with that obtained from the bulk magnetization measurements.

28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex