Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Parametric resonance of a two-dimensional electron gas under bichromatic
  irradiation   In an ultrahigh mobility 2D electron gas, even a weak nonparabolicity of the
electron dispersion, by violating Kohn's theorem, can have a drastic effect on
dc magnetotransport under ac drive. We study theoretically the manifestation of
this effect in the dc response to the combined action of two driving ac-fields
(bichromatic irradiation). Compared to the case of monochromatic irradiation,
which is currently intensively studied both experimentally and theoretically,
the presence of a second microwave source provides additional insight into the
properties of an ac-driven 2D electron gas. In particular, we find that
nonparabolicity, being the simplest cause for a violation of Kohn's theorem,
gives rise to new qualitative effects specific to bichromatic irradiation.
Namely, when the frequencies $\omega_1$ and $\omega_2$ are well away from the
cyclotron frequency, $\omega_c$, our simple classical considerations
demonstrate that the system becomes parametrically unstable with respect to
fluctuations with frequency $(\omega_1+\omega_2)/2$. As an additional effect of
nonparabolicity, this parametric instability can manifest itself in the dc
properties of the system. This happens when $\omega_1$, $\omega_2$ and
$\omega_c$ are related as 3:1:2, respectively. Even for weak detuning between
$\omega_1$ and $\omega_2$, the effect of the bichromatic irradiation on the dc
response in the presence of nonparabolicity can differ dramatically from the
monochromatic case. In particular, the equations of motion can acquire
multistable solutions. As a result, the diagonal dc-conductivity can assume
several stable negative values at the same magnetic field.

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The categories of this paper are: math
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci