245 research outputs found
Limitations on the attainable intensity of high power lasers
It is shown that even a single pair created by a super strong laser
field in vacuum would cause development of an avalanche-like QED cascade which
rapidly depletes the incoming laser pulse. This confirms the old N. Bohr
conjecture that the electric field of the critical QED strength
could never be created.Comment: 4 pages, 3 figure
Creation of electron-positron plasma with superstrong laser field
We present a short review of recent progress in studying QED effects of
interaction of ultra-relativistic laser pulses with vacuum and plasma.
The development of laser technologies promises very rapid growth of laser
intensities in close future already. Two exawatt class facilities (ELI and
XCELS, Russia) in Europe are already in the planning stage. Realization of
these projects will make available a laser of intensity W/cm
or even higher. Therefore, discussion of nonlinear optical effects in vacuum
are becoming urgent for experimentalists and are currently gaining much
attention. We show that, in spite of the fact that the respective field
strength is still essentially less than V/cm, the nonlinear vacuum effects will be accessible for observation
at ELI and XCELS facilities. The most promissory for observation is the effect
of pair creation by laser pulse in vacuum. It is shown, that at intensities
W/cm, creation even of a single pair is accompanied by
development of an avalanchelike QED cascade. There exists an important
distinctive feature of the laser-induced cascades, as compared with the air
showers arising due to primary cosmic ray entering the atmosphere. In our case
the laser field plays not only the role of a target (similar to a nucleus in
the case of air showers). It is responsible also for acceleration of slow
particles. It is shown that the effect of pair creation imposes a natural limit
for attainable laser intensity. Apparently, the field strength is
not accessible for pair creating electromagnetic field at all.Comment: To be published in digest "IZEST Scientific Case" in EPJ ST early
201
Coulomb effects in electronic transport
Charge transport in metals and semiconductors is often dominated by electron-impurity and electron–phonon scattering. Coulomb effects could be found in small corrections to the leading behavior, drag effects in specially fabricated samples, compensated semimetals, and hydrodynamic phenomena in ultra-pure materials. In contrast, electrical resistivity in strongly correlated systems is poorly understood. Understanding the fate of electron–phonon scattering in these materials may offer a route towards future advancements
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