Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological semimetals with Riemann surface states   Riemann surfaces are geometric constructions in complex analysis that may
represent multi-valued holomorphic functions using multiple sheets of the
complex plane. We show that the energy dispersion of surface states in
topological semimetals can be represented by Riemann surfaces generated by
holomorphic functions in the two-dimensional momentum space, whose constant
height contours correspond to Fermi arcs. This correspondence is demonstrated
in the recently discovered Weyl semimetals and leads us to predict new types of
topological semimetals, whose surface states are represented by double- and
quad-helicoid Riemann surfaces. The intersection of multiple helicoids, or the
branch cut of the generating function, appears on high-symmetry lines in the
surface Brillouin zone, where surface states are guaranteed to be doubly
degenerate by a glide reflection symmetry. We predict the heterostructure
superlattice [(SrIrO$_3$)$_2$(CaIrO$_3$)$_2$] to be a topological semimetal
with double-helicoid Riemann surface states.

15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
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The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph