Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theoretical and experimental evidence of a site-selective Mott
  transition in Fe2O3 under pressure   We provide experimental and theoretical evidence for a novel type of
pressure-induced insulator-metal transition characterized by site-selective
delocalization of the electrons. M\"ossbauer spectroscopy, X-ray diffraction
and electrical transport measurements on Fe$_2$O$_3$ to 100 GPa, along with
dynamical mean-field theory (DFT+DMFT) calculations, reveal this site-selective
Mott transition between 50 and 68 GPa, such that the metallization can be
described by ($^\rm{VI}$Fe$^{3+\rm{HS}}$)$_2$O$_3$ [$R\bar{3}c$ structure]
$\overrightarrow{\tiny\rm{50~GPa}}$
($^\rm{VIII}$Fe$^{3+\rm{HS~VI}}$Fe$^\rm{M}$)O$_3$ [$P2_1/n$ structure]
$\overrightarrow{\tiny\rm{68~GPa}}$ ($^\rm{VI}$Fe$^\rm{M}$)$_2$O$_3$ [$Aba2$
structure]. Within the $P2_1/n$ crystal structure, characterized by two
distinct coordination sites (VI and VIII), we observe equal abundances of
ferric ions (Fe$^{3+}$) and ions having delocalized electrons (Fe$^\rm{M}$),
and only at higher pressures is a fully metallic $Aba2$ structure obtained, all
at room temperature. The transition is characterized by
delocalization/metallization of the $3d$ electrons on half the Fe sites, with a
site-dependent collapse of local moments. Above $\sim$50 GPa, Fe$_2$O$_3$ is a
strongly correlated metal with reduced electron mobility (large band
renormalizations) of m*/m$\sim$4 and 6 near the Fermi level. Upon
decompression, we observe a site-selective (metallic) to conventional Mott
insulator phase transition ($^\rm{VIII}$Fe$^{3+\rm{HS~VI}}$Fe$^\rm{M}$)O$_3$
$\overrightarrow{\tiny\rm{50~GPa}}$ ($^\rm{VIII}$Fe$^{3+\rm{HS~VI}}$Fe$^{3+
\rm{HS}}$)O$_3$ within the same $P2_1/n$ structure, indicating a decoupling of
the electronic and lattice degrees of freedom, characteristic of a true Mott
transition. Our results show that the interplay of electronic correlations and
lattice may result in rather complex behavior of the electronic structure and
magnetic state.

14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
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The categories of this paper are: stat
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: mtrl-th