Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New quantum MDS codes derived from constacyclic codes   Quantum maximal-distance-separable (MDS) codes form an important class of
quantum codes. It is very hard to construct quantum MDS codes with relatively
large minimum distance. In this paper, based on classical constacyclic codes,
we construct two classes of quantum MDS codes with parameters
$$[[\lambda(q-1),\lambda(q-1)-2d+2,d]]_q$$ where $2\leq d\leq
(q+1)/2+\lambda-1$, and $q+1=\lambda r$ with $r$ even, and
$$[[\lambda(q-1),\lambda(q-1)-2d+2,d]]_q$$ where $2\leq d\leq
(q+1)/2+\lambda/2-1$, and $q+1=\lambda r$ with $r$ odd. The quantum MDS codes
exhibited here have parameters better than the ones available in the
literature.

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The categories of this paper are: hep-th
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The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph