Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermal quantum discord in the Heisenberg chain with impurity   We study thermal quantum discord (TQD) in the Heisenberg chain with spin site
or magnetic impurity. The former one of which may induce inhomogeneous exchange
interactions between the neighboring spins, while the latter one modelling a
spin chain with nonuniform magnetic field. In contrast with one's traditional
understanding, we found that the spin impurity can be used to enhance the TQD
greatly for all the bipartition schemes of the chain, while the magnetic
impurity located on one spin can make the TQD between the other two spins
approaching its maximum 1 for the antiferromagnetic chain.

2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn