Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Valence state manipulation of single Fe impurities in GaAs by STM
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th