Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Are Quantum-Cascade Lasers really quantum?   The first global simulation of semiconductor-based quantum-cascade lasers is
presented; Our fully three-dimensional approach allows to study in a purely
microscopic way -without resorting to phenomenological parameters- the
current-voltage characteristics of state-of-the-art unipolar nanostructures.
Based on the proposed theoretical scheme, we are able to give a definite answer
to the long-standing controversial question: is charge transport in
quantum-cascade lasers mainly coherent or incoherent? Our analysis clearly
shows that a proper inclusion of carrier-phonon as well as carrier-carrier
scattering within a semiclassical framework gives excellent agreement with
experimental results.

7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas