Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: I-V characteristics of the vortex state in MgB2 thin films   The current-voltage (I-V) characteristics of various MgB2 films have been
studied at different magnetic fields parallel to c-axis. At fields \mu0H
between 0 and 5T, vortex liquid-glass transitions were found in the I-V
isotherms. Consistently, the I-V curves measured at different temperatures show
a scaling behavior in the framework of quasi-two-dimension (quasi-2D) vortex
glass theory. However, at \mu0 H >= 5T, a finite dissipation was observed down
to the lowest temperature here, T=1.7K, and the I-V isotherms did not scale in
terms of any known scaling law, of any dimensionality. We suggest that this may
be caused by a mixture of \sigma band vortices and \pi band quasiparticles.
Interestingly, the I-V curves at zero magnetic field can still be scaled
according to the quasi-2D vortex glass formalism, indicating an equivalent
effect of self-field due to persistent current and applied magnetic field.

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The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
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The categories of this paper are: econ
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
9
The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: math
1
The categories of this paper are: cs
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The categories of this paper are: chao-dyn
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The categories of this paper are: physics
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The categories of this paper are: q-alg
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The categories of this paper are: eess