Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Charge disproportionation and Hund's insulating behavior in a
  five-orbital Hubbard model applicable to $d^4$ perovskites   We explore the transition to a charge-disproportionated insulating phase in a
five-orbital cubic tight-binding model applicable to transition-metal
perovskites with a formal $d^4$ occupation of the transition-metal cation, such
as ferrates or manganites. We use dynamical mean-field theory to obtain the
phase diagram as a function of the average local Coulomb repulsion $U$ and the
Hund's coupling $J$. The main structure of the phase diagram follows from the
zero band-width (atomic) limit and represents the competition between high-spin
and low-spin homogeneous and an inhomogeneous charge-disproportionated state.
This results in two distinct insulating phases: the standard homogeneous Mott
insulator and the inhomogeneous charge-disproportionated insulator, recently
also termed Hund's insulator. We characterize the unconventional nature of this
Hund's insulating state. Our results are consistent with previous studies of
two- and three-orbital models applicable to isolated $t_{2g}$ and $e_g$
subshells, respectively, with the added complexity of the low-spin/high-spin
transition. We also test the applicability of an effective two-orbital
($e_g$-only) model with disordered $S=3/2$ $t_{2g}$ core spins. Our results
show that the overall features of the phase diagram in the high-spin region are
well described by this simplified two-orbital model but also that the spectral
features exhibit pronounced differences compared to the full five-orbital
description.

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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con
19
The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
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The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
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The categories of this paper are: atom-ph