558 research outputs found
Long-range correlation-induced effects at high-order harmonic generation on graphene quantum dots
This paper focuses on investigating high-order harmonic generation (HHG) in
graphene quantum dots (GQDs) under intense near-infrared laser fields. To model
the GQD and its interaction with the laser field, we utilize a mean-field
approach. Our analysis of the HHG power spectrum reveals fine structures and a
noticeable enhancement in cutoff harmonics due to the long-range correlations.
We also demonstrate the essential role of Coulomb interaction in determining of
harmonics intensities and cutoff position. Unlike atomic HHG, where the cutoff
energy is proportional to the pump wave intensity, in GQDs the cutoff energy
scales with the square root of the field strength amplitude. A detailed
time-frequency analysis of the entire range of HHG spectrum is presented using
a wavelet transform. The analysis reveals intricate details of the spectral and
temporal fine structures of HHG, offering insights into the various HHG
mechanisms in GQDs.Comment: 10 pages, 15 figure
Essential L-Amino Acid-Functionalized Graphene Oxide for Liquid Crystalline Phase Formation
The colloidal 2D materials based on graphene and its modifications are of
great interest when it comes to forming LC phases. These LC phases allow
controlling the orientational order of colloidal particles, paving the way for
the efficient processing of modified graphene with anisotropic properties.
Here, we present the peculiarities of AA functionalization of GO, along with
the formation of its LC phase and orientational behavior in an external
magnetic field. We discuss the influence of pH on the GOLC, ultimately showing
its pH-dependent behavior for GO-AA complexes. In addition, we observe
different GO morphology changes due to the presence of AA functional groups,
namely L-cysteine dimerization on the GO platform. The pH dependency of
AA-functionalized LC phase of GO is examined for the first time. We believe
that our studies will open new possibilities for applications in
bionanotechnologies due to self-assembling properties of LCs and magnificent
properties of GO.Comment: 10 pages, 16 figure
Options for Scaling up Community-Based Health Insurance for Rural Communities in Armenia
This paper summarises the results of a study which examined international experience with regard to community-based health financing (CBHF) schemes, scaling up CBHF schemes, and the feasibility of scaling up community-based health insurance (CBHI) in Armenia. It was based on a literature review of international experience and qualitative research in Armenia. The recommendations derived from this study have relevance both for Armenia and for the use of CBHI schemes as a tool for promoting pro-poor health system reform in low-resource settings more generally
Demkov-Kunike model for cold atom association: weak interaction regime
We study the nonlinear mean-field dynamics of molecule formation at coherent
photo- and magneto-association of an atomic Bose-Einstein condensate for the
case when the external field configuration is defined by the quasi-linear level
crossing Demkov-Kunike model, characterized by a bell-shaped pulse and finite
variation of the detuning. We present a general approach to construct an
approximation describing the temporal dynamics of the molecule formation in the
weak interaction regime and apply the developed method to the nonlinear
Demkov-Kunike problem. The presented approximation, written as a scaled
solution to the linear problem associated to the nonlinear one we treat,
contains fitting parameters which are determined through a variational
procedure. Assuming that the parameters involved in the solution of the linear
problem are not modified, we suggest an analytical expression for the scaling
parameter.Comment: 6 pages, 4 figure
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