Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Direct observation of the layer-number-dependent electronic structure in
  few-layer WTe2   When a crystal becomes thinner and thinner to the atomic level, peculiar
phenomena discretely depending on its layer-numbers (n) start to appear. The
symmetry and wave functions strongly reflect the layer-numbers and stacking
order, which brings us a potential of realizing new properties and functions
that are unexpected in either bulk or simple monolayer. Multilayer WTe2 is one
such example exhibiting unique ferroelectricity and non-linear transport
properties related to the antiphase stacking and Berry-curvature dipole. Here
we investigate the electronic band dispersions of multilayer WTe2 (2-5 layers),
by performing laser-based micro-focused angle-resolved photoelectron
spectroscopy on exfoliated-flakes that are strictly sorted by n and
encapsulated by graphene. We clearly observed the insulator-semimetal
transition occurring between 2- and 3-layers, as well as the 30-70 meV
spin-splitting of valence bands manifesting in even n as a signature of
stronger structural asymmetry. Our result fully demonstrates the possibility of
the large energy-scale band and spin manipulation through the finite n stacking
procedure.

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The categories of this paper are: hep-lat
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The categories of this paper are: econ
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph