Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Influence of surface irregularities on barriers for vortex entry in
  type-II superconductors   A theoretical description of the influence of surface irregularities (such as
wedge-like cracks) on the Bean-Livingston energy barrier is presented. A
careful quantitative estimate of the field of the first vortex entry H* into a
homogeneous bulk superconductor with crack-like defects is obtained. This
estimate is based on an exact analytical solution for the Meissner current
distribution in a bulk superconductor with a single two-dimensional infinitely
thin crack. This thin crack is characterized by the lowest H* value, and, thus,
appears to be the best gate for vortex entry.

23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin