Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Role of Nonlocality in the Pinning Properties of Borocarbides
  Materials   An experimental review on the influence of nonlocal electrodynamics in the
vortex pinning properties of non-magnetic borocarbide superconductors is
presented. We show that the pinning force density Fp exhibits a rich and
complex anisotropic behavior that sharply contrast with the small mass
anisotropy of these compounds. For magnetic fields H applied parallel to the
crystallographic c-axis, the first order reorientation transition between two
rhombic lattices manifests itself as a kink in Fp(H). For H perpendicular to
the c-axis, a much larger Fp(H) and a slower relaxation rate is observed. In
this field configuration, nonlocality induces a fourfold periodicity in Fp when
H is rotated within the square basal plane. Unlike the out-of-plane anisotropy,
which persists for increasing impurity levels, the in-plane fourfold anisotropy
can be strongly suppressed by reducing the electronic mean free path. This
result unambiguously demonstrate that the in-plane anisotropy is a consequence
of nonlocal effects.

2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex