Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-dimensional semimetal in a wide HgTe quantum well: magnetotransport
  and energy spectrum   The results of experimental study of the magnetoresistivity, the Hall and
Shubnikov-de Haas effects for the heterostructure with HgTe quantum well of
20.2 nm width are reported. The measurements were performed on the gated
samples over the wide range of electron and hole densities including vicinity
of a charge neutrality point. Analyzing the data we conclude that the energy
spectrum is drastically different from that calculated in framework of
$kP$-model. So, the hole effective mass is equal to approximately $0.2 m_0$ and
practically independent of the quasimomentum ($k$) up to $k^2\gtrsim 0.7\times
10^{12}$ cm$^{-2}$, while the theory predicts negative (electron-like)
effective mass up to $k^2=6\times 10^{12}$ cm$^{-2}$. The experimental
effective mass near k=0, where the hole energy spectrum is electron-like, is
close to $-0.005 m_0$, whereas the theoretical value is about $-0.1 m_0$.

11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org