Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Spin transport and accumulation in the persistent photoconductor
  Al$_{0.3}$Ga$_{0.7}$As
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
16
The categories of this paper are: stat