Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Temperature-driven modification of surface electronic structure on
  bismuth, a topological border material   Single crystalline bismuth (Bi) is known to have a peculiar electronic
structure which is very close to the topological phase transition. The
modification of the surface states of Bi depending on the temperature are
revealed by angle-resolved photoelectron spectroscopy (ARPES). At low
temperature, the upper branch of the surface state merged to the projected bulk
conduction bands around the $\bar{M}$ point of the surface Brillouin zone
(SBZ). In contrast, the same branch merged to the projected bulk valence bands
at high temperature (400 K). Such behavior could be interpreted as a
topological phase transition driven by the temperature, which might be
applicable for future spin-thermoelectric devices. We discuss the possible
mechanisms to cause such transition, such as the thermal lattice distortion and
electron-phonon coupling.

6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
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The categories of this paper are: eess
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs