Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermoelectric effects in superconductors   It is widely believed that temperature gradient does not induce electric
field in the superconductor and consequently that thermoelectric effects do not
exist, or are negligible in these materials. This statement is correct only as
far as effective electric field or gradient of the electrochemical potential is
concerned. In normal metals temperature gradient generates effective electric
field, which nulls out thermally induced diffusion current. In superconductor
the diffusion current of quasiparticles is canceled a counterflow of
supercurrent. Superconducting current induces the true electric field, which
can be approximated by gradient of the screened Bernoulli potential. It
explains familiar giant thermomagnetic flux observed in superconducting
thermocouples. Contactless measurements of thermoelectric effects are
suggested.

9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat