Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological Phase Transition Induced by Image Potential States in
  MXenes: A Theoretical Investigation   MXenes, a family of two-dimensional transition metal carbides and nitrides,
have various tunable physical and chemical properties. Their diverse
prospective applications in electronics and energy storage devices have
triggered great interests in science and technology. MXenes can be
functionalized by different surface terminations. Some O and F functionalized
MXenes monolayers have been predicted to be topological insulators (TIs).
However, the reported OH functionalized MXenes TIs are very few and their
electronic structures need to be investigated in more detail. It has been
revealed that the work functions of MXenes are reduced significantly by OH
termination and the image potential (IP) states move close to the Fermi level.
The wave functions of these IP states are spatially extensive outside the
surfaces. By stacking the OH-functionalized MXenes, the energies of the IP
states can be modulated by the interlayer distances of multilayers, because the
overlap and hybridization of the wave functions between the neighboring layers
are significant. Therefore, these stacking layers are interacted and coupled
with IP states. Here, based on first-principles calculations, we demonstrate
that the stacking of two-dimensional topologically trivial OH-functionalized
MXenes, such as V$_2$HfC$_2$(OH)$_2$, possibly gives rise to the topologically
nontrivial energy bands. In other words, the topological properties of
V$_2$HfC$_2$(OH)$_2$ multilayers can be modulated by its interlayer distance.
An energy band inversion involving IP states is proposed. We expect that these
results can advance the future application of MXenes or other low work function
multilayer materials as controllable TI devices.

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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: quant-ph
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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: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: cs
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The categories of this paper are: plasm-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph