Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-site fluctuations and multipolar superexchange interactions in
  strongly correlated systems   An approach is proposed for evaluating dipolar and multipolar inter-site
interactions in strongly correlated materials. This approach is based on the
single-site dynamical mean-field theory (DMFT) in conjunction with the atomic
approximation for the local self-energy. Starting from the local moment
paramagnetic state described by DMFT we derive inter-site interactions by
considering the response of the DMFT grand potential to small fluctuations of
atomic configurations on two neighboring sites. The present method is validated
by applying it to one-band and two-band e$_g$ Hubbard models on the
simple-cubic 3$d$ lattice. It is also applied to study the spin-orbital order
in the parent cubic structure of ternary chromium fluoride KCrF$_3$. We obtain
the onset of a G-type antiferro-orbital order at a significantly lower
temperature compared to that in real distorted KCrF$_3$. In contrast, its
layered A-type antiferromagnetic order and N\'eel temperature are rather well
reproduced. The calculated full Kugel-Khomskii Hamiltonian contains
spin-orbital coupling terms inducing a misalignment in the antiferro-orbital
order upon the onset of antiferromagnetism.

32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph