Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-monotonic magnetoresistance of two-dimensional electron systems in
  the ballistic regime   We report experimental observations of a novel magnetoresistance (MR)
behavior of two-dimensional electron systems in perpendicular magnetic field in
the ballistic regime, for k_BT\tau/\hbar>1. The MR grows with field and
exhibits a maximum at fields B>1/\mu, where \mu is the electron mobility. As
temperature increases the magnitude of the maximum grows and its position moves
to higher fields. This effect is universal: it is observed in various Si- and
GaAs- based two-dimensional electron systems. We compared our data with recent
theory based on the Kohn anomaly modification in magnetic field, and found
qualitative similarities and discrepancies.

30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th