Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hopping induced ground-state magnetism in 6H perovskite iridates   Investigation of elementary excitations has advanced our understanding of
many-body physics governing most physical properties of matter. Recently
spin-orbit excitons have drawn much attention, whose condensates near phase
transitions exhibit Higgs mode oscillations, a long-sought physical phenomenon
[Nat. Phys. {\bf 13}, 633 (2017)]. These critical transition points resulting
from competing spin-orbit coupling (SOC), local crystalline symmetry and
exchange interactions, are not obvious in Iridium based materials, where SOC
prevails in general. Here, we present results of resonant inelastic x-ray
scattering on a spin-orbital liquid Ba$_3$ZnIr$_2$O$_9$ and three other
6H-hexagonal perovskite iridates which show magnetism, contrary to non-magnetic
singlet ground state expected due to strong SOC. Our results show that
substantial hopping between closely placed Ir$^{5+}$ ions within Ir$_2$O$_9$
dimers in these 6H-iridates, modifies spin-orbit coupled states and reduces
spin-orbit excitation energies. Here, we are forced to use at least a two-site
model, to match the excitation spectrum going in line with the strong
intra-dimer hopping. Apart from SOC, low energy physics of iridates is thus
critically dependent on hopping, and may not be ignored even for systems having
moderate hopping, where the excitation spectra can be explained using an atomic
model. SOC which is generally found to be 0.4-0.5~eV in iridates, is scaled in
effect down to $\sim$0.26~eV for the 6H-systems, sustaining the hope to achieve
quantum criticality by tuning Ir-Ir separation.

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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: econ
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The categories of this paper are: nlin
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an