Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electrical conductivity beyond linear response in layered
  superconductors under magnetic field   The time-dependent Ginzburg-Landau approach is used to investigate nonlinear
response of a strongly type-II superconductor. The dissipation takes a form of
the flux flow which is quantitatively studied beyond linear response. Thermal
fluctuations, represented by the Langevin white noise, are assumed to be strong
enough to melt the Abrikosov vortex lattice created by the magnetic field into
a moving vortex liquid and marginalize the effects of the vortex pinning by
inhomogeneities. The layered structure of the superconductor is accounted for
by means of the Lawrence-Doniach model. The nonlinear interaction term in
dynamics is treated within Gaussian approximation and we go beyond the often
used lowest Landau level approximation to treat arbitrary magnetic fields. The
I-V curve is calculated for arbitrary temperature and the results are compared
to experimental data on high-$T_{c}$ superconductor
YBa$_{2}$Cu$_{3}$O$%_{7-\delta}$.

20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom