Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electron correlations in two-dimensional small quantum dots   We consider circular and elliptic quantum dots with parabolic external
confinement, containing 0 - 22 electrons and with values of r_s in the range 0
< r_s < 3. We perform restricted and unrestricted Hartree-Fock calculations,
and further take into account electron correlations using second-order
perturbation theory. We demonstrate that in many cases correlations
qualitatively change the spin structure of the ground state from that obtained
under Hartree-Fock and spin-density-functional calculations. In some cases the
correlation effects destroy Hund's rule. We also demonstrate that the
correlations destroy static spin-density waves observed in Hartree-Fock and
spin-density-functional calculations.

20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas