126,643 research outputs found
Density domains of a photo-excited electron gas on liquid helium
The Coulombic effect on the stability range of the photo-excited electron gas
on liquid helium is shown to favor formation of domains of different densities.
Domains appear to eliminate or greatly reduce regions with negative
conductivity. An analysis of the density domain structure allows explaining
remarkable observations reported recently for the photo-excited electron gas.Comment: 5 pages, 5 figure
Statistical Ensembles with Fluctuating Extensive Quantities
We suggest an extension of the standard concept of statistical ensembles.
Namely, we introduce a class of ensembles with extensive quantities fluctuating
according to an externally given distribution. As an example the influence of
energy fluctuations on multiplicity fluctuations in limited segments of
momentum space for a classical ultra-relativistic gas is considered.Comment: 4 pages, 2 figure
Electric-field-induced monoclinic phase in (Ba,Sr)TiO thin film
We have studied electric-field-induced symmetry lowering in the tetragonal
(001)-oriented heteroepitaxial (BaSr)TiO thin film
deposited on (001)MgO substrate. Polarized micro-Raman spectra were recorded
from the film area in between two planar electrodes deposited on the film
surface. Presence of \textit{c}-domains with polarization normal to the
substrate was confirmed from polarized Raman study under zero field, while
splitting and hardening of the \textit{E}(TO) soft mode and polarization
changes in the Raman spectra suggest monoclinic symmetry under external
electric field
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