Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic quantum ratchet effect in (Cd,Mn)Te- and CdTe-based quantum
  well structures with a lateral asymmetric superlattice   We report on the observation of magnetic quantum ratchet effect in (Cd,Mn)Te-
and CdTe-based quantum well structures with an asymmetric lateral dual grating
gate superlattice subjected to an external magnetic field applied normal to the
quantum well plane. A dc electric current excited by cw terahertz laser
radiation shows 1/B-oscillations with an amplitude much larger as compared to
the photocurrent at zero magnetic field. We show that the photocurrent is
caused by the combined action of a spatially periodic in-plane potential and
the spatially modulated radiation due to the near field effects of light
diffraction. Magnitude and direction of the photocurrent are determined by the
degree of the lateral asymmetry controlled by the variation of voltages applied
to the individual gates. The observed magneto-oscillations with enhanced
photocurrent amplitude result from Landau quantization and, for (Cd,Mn)Te at
low temperatures, from the exchange enhanced Zeeman splitting in diluted
magnetic heterostructures. Theoretical analysis, considering the magnetic
quantum ratchet effect in the framework of semiclassical approach, describes
quite well the experimental results.

11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess