Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: AlAs 2D electrons in an antidot lattice: Electron pinball with
  elliptical Fermi contours   We report ballistic transport measurements in a two-dimensional electron
system confined to an AlAs quantum well and patterned with square antidot
lattices of period $a = $0.6, 0.8, 1.0 and 1.5 $\mu$m. In this system two
in-plane conduction-band valleys with elliptical Fermi contours are occupied.
The low-field magneto-resistance traces exhibit peaks corresponding to the
commensurability of the cyclotron orbits and the antidot lattice. From the
dependence of the position of the peak associated with the smallest
commensurate orbit on electron density and $a$, we deduce the ratio of the
longitudinal and transverse effective masses $m_l/m_t=5.2\pm 0.4$, a
fundamental parameter for the anisotropic conduction bands in AlAs.

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The categories of this paper are: stat
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
3
The categories of this paper are: physics
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an