Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetry of anisotropic exchange interactions in semiconductor
  nanostructures   The symmetry of exchange interaction of charge carriers in semiconductor
nanostructures (quantum wells and quantum dots) is analysed. It is shown that
the exchange Hamiltonian of two particles belonging to the same energy band can
be universally expressed via pseudospin operators of the particles. The
relative strength of the anisotropic exchange interaction is shown to be
independent of the binding energy and the isotropic exchange constant.

27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci