Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tunneling Spectroscopy and Vortex Imaging in Boron-Doped Diamond   We present the first scanning tunneling spectroscopy study of
single-crystalline boron doped diamond. The measurements were performed below
100 mK with a low temperature scanning tunneling microscope. The tunneling
density of states displays a clear superconducting gap. The temperature
evolution of the order parameter follows the weak coupling BCS law with
$\Delta(0)/k_B T_c \simeq 1.74$. Vortex imaging at low magnetic field also
reveals localized states inside the vortex core that are unexpected for such a
dirty superconductor.

29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol