Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum lifetime of 2D electron in magnetic field   The lifetime of two dimensional electrons in GaAs quantum wells, placed in
weak quantizing magnetic fields, is measured using a simple transport method in
broad range of temperatures from 0.3 K to 20 K. The temperature variations of
the electron lifetime are found to be in good agreement with conventional
theory of electron-electron scattering in 2D systems.

19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn