Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Temperature performance analysis of terahertz quantum cascade lasers:
  Vertical versus diagonal designs   Resonant phonon depopulation terahertz quantum cascade lasers based on
vertical and diagonal lasing transitions are systematically compared using a
well established ensemble Monte Carlo approach. The analysis shows that for
operating temperatures below 200 K, diagonal designs may offer superior
temperature performance at lasing frequencies of about 3.5 THz and above;
however, vertical structures are more advantageous for good temperature
performance at lower frequencies.

6
The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio