Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theory of topological excitations and metal-insulator transition in
  reentrant integer quantum Hall effect   The reentrant integer quantum Hall effects (RIQHE) are due to formation of
electronic crystals. We show analytically and numerically that topological
textures in the charge density distribution in these crystals in the vicinity
of charged defects strongly reduce energy required for current-carrying
excitations. The theory quantitatively explains sharp insulator-metal
transitions experimentally observed in RIQHE states. The insulator to metal
transition in RIQHE emerges as a thermodynamic unbinding transition of
topological charged defects.

27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg