Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strain Effects in Topological Insulators: Topological Order and the
  Emergence of Switchable Topological Interface States in
  Sb$_2$Te$_3$/Bi$_2$Te$_3$ Heterojunctions   Strain can induce a topological phase transition in bismuth dichalcogenides.
We present the phase diagram for 3D topological insulators Bi$_2$Te$_3$,
Sb$_2$Te$_3$, Bi$_2$Se$_3$ and Sb$_2$Se$_3$ with uniaxial and biaxal strain,
which show metallic and insulating phases, both topologically trivial and
non-trivial. In particular, uniaxial tension can drive Sb$_2$Te$_3$ into a
topologically trivial insulating phase. Thus, we propose a
Sb$_2$Te$_3$/Bi$_2$Te$_3$ heterojunction in which a topological interface state
arises in the common gap of this topological insulator-normal insulator
heterojunction that can be switched on or off by means of uniaxial strain. This
interface state is confined in the Sb$_2$Te$_3$ subsystem and is physically
protected from ambient impurities. Therefore, Sb$_2$Te$_3$/Bi$_2$Te$_3$
heterojunctions can host robust helical interface states with promising
spintronic applications.

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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph