Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Engineering Time-Reversal Invariant Topological Insulators With
  Ultra-Cold Atoms   Topological insulators are a broad class of unconventional materials that are
insulating in the interior but conduct along the edges. This edge transport is
topologically protected and dissipationless. Until recently, all existing
topological insulators, known as quantum Hall states, violated time-reversal
symmetry. However, the discovery of the quantum spin Hall effect demonstrated
the existence of novel topological states not rooted in time-reversal
violations. Here, we lay out an experiment to realize time-reversal topological
insulators in ultra-cold atomic gases subjected to synthetic gauge fields in
the near-field of an atom-chip. In particular, we introduce a feasible scheme
to engineer sharp boundaries where the "edge states" are localized. Besides,
this multi-band system has a large parameter space exhibiting a variety of
quantum phase transitions between topological and normal insulating phases. Due
to their unprecedented controllability, cold-atom systems are ideally suited to
realize topological states of matter and drive the development of topological
quantum computing.

3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-lat