Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chiral Optical Response of Multifold Fermions   Multifold fermions are generalizations of two-fold degenerate Weyl fermions
with three-, four-, six- or eight-fold degeneracies protected by crystal
symmetries, of which only the last type is necessarily non-chiral. Their low
energy degrees of freedom can be described as emergent particles not present in
the Standard Model of particle physics. We propose a range of experimental
probes for multifold fermions in chiral symmetry groups based on the gyrotropic
magnetic effect (GME) and the circular photo-galvanic effect (CPGE). We find
that, in contrast to Weyl fermions, multifold fermions can have zero Berry
curvature yet a finite GME, leading to an enhanced response. The CPGE is
quantized and independent of frequency provided that the frequency region at
which it is probed defines closed optically-activated momentum surfaces. We
confirm the above properties by calculations in symmetry-restricted tight
binding models with realistic density functional theory parameters. We identify
a range of previously-unidentified ternary compounds able to exhibit chiral
multifold fermions of all types (including a range of materials in the families
AsBaPt and Gd$_3$Cl$_3$C), and provide specific predictions for the known
multifold material RhSi.

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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
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The categories of this paper are: nlin
37
The categories of this paper are: supr-con
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: econ