Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Impurity-induced frustration: low-energy model of diluted oxides   We provide a detailed derivation of the low-energy model for Zn-diluted
La2CuO4 in the limit of low doping together with a study of the ground-state
properties of that model. We consider Zn-doped La2CuO4 within a framework of
the three-band Hubbard model, which closely describes high-Tc cuprates on the
energy scale of the most relevant atomic orbitals. Qualitatively, we find that
the hybridization of zinc and oxygen orbitals can result in an impurity state
with the energy \varepsilon, which is lower than the effective Hubbard gap U.
The low-energy, spin-only Hamiltonian includes terms of the order t^2/U and
t^4/\varepsilon^3. That is, besides the usual nearest-neighbor superexchange
J-terms of order t^2/U, the low-energy model contains impurity-mediated,
further-neighbor frustrating interactions among the Cu spins surrounding
Zn-sites in an otherwise unfrustrated antiferromagnetic background. These terms
can be substantial when \varepsilon ~ U/2, the latter value corresponding to
the realistic CuO2 parameters. In order to verify this spin-only model, we
subsequently apply the T-matrix approach to study the effect of impurities on
the antiferromagnetic order parameter. Previous theoretical studies, which
include only the dilution effect of impurities, show a large discrepancy with
experimental data in the doping dependence of the staggered magnetization at
low doping. We demonstrate that this discrepancy is eliminated by including
impurity-induced frustrations into the effective spin model with realistic CuO2
parameters. Recent experimental study shows a significantly stronger
suppression of spin stiffness in the case of Zn-doped La2CuO4 compared to the
Mg-doped case and thus gives a strong support to our theory. We argue that the
proposed impurity-induced frustrations should be important in other strongly
correlated oxides and charge-transfer insulators.

20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
9
The categories of this paper are: nlin
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The categories of this paper are: eess
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat