Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Creep in Y_{1-x}Pr_{x}Ba_{2}Cu_{3}O_{7}$ Crystals: Magnetic
  Relaxation and Transport   We report transport and magnetic relaxation measurements in the mixed state
of strongly underdoped Y_{1-x}Pr_{x}Ba_{2}Cu_{3}O_{7} crystals. A transition
from thermally activated flux creep to temperature independent quantum flux
creep is observed in both transport and magnetic relaxation at temperatures T *
5 K. Flux transformer measurements indicate that the crossover to quantum creep
is preceded by a coupling transition. Based on these observations we argue that
below the coupling transition the current is confined within a very narrow
layer beneath the current contacts.

15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
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The categories of this paper are: eess
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph