Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Flux quanta driven by high-density currents in low-impurity V3Si and
  LuNi2B2C: free flux flow and flux-core size effect   High density direct currents (DC) are used to drive flux quanta via the
Lorentz force towards a highly ordered "free flux flow" (FFF) dynamic state,
made possible by the weak-pinning environment of high-quality, single-crystal
samples of two low-Tc superconducting compounds, V3Si and LuNi2B2C. We report
the effect of the magnetic field-dependent fluxon core size on flux flow
resistivity rho_f. Much progress has been made in minimizing the technical
challenges associated with the use of high currents. Attainment of a FFF phase
is indicated by the saturation at highest currents of flux-flow dissipation
levels that are well below the normal state resistance and have field-dependent
values. The field dependence of the corresponding rho_f is shown to be
consistent with a prediction based on a model for the decrease of flux core
size at higher fields in weak-coupling BCS s-wave materials.

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The categories of this paper are: solv-int
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The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph