Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Improving the quality of spatial quantum channels   We show, for the non-Markovian or time-dependent Markovian process, by
breaking up a spatial quantum channel (SQC) into a series of periodically
arranged sub-components, that the quality of information transmission described
by the purity, fidelity and concurrence of the output states can be improved.
The relation to the quantum zero effect and possible applications of the idea
have been discussed.

30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th