Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Local investigation of the energy gap within the incompressible strip in
  the quantum Hall regime   We experimentally study the energy gap within the incompressible strip at
local filling factor $\nu_c=1$ at the quantum Hall edge for samples of very
different mobilities. The obtained results indicate strong enhancement of the
energy gap in comparison to the single-particle Zeeman splitting. We identify
the measured gap as a mobility gap, so a pronounced experimental in-plane
magnetic field dependence can both be attributed to the spin effects as well as
to the change in the energy levels broadening.

13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin