[Todos] CLUB DE MATERIA CONDENSADA HOY 13.30
Gustavo S Lozano
lozano en df.uba.ar
Vie Mayo 9 11:06:35 ART 2008
CLUB DE MATERIA CONDENSADA
Seguimos con el club el VIERNES 9 a las 13.30 en el aula de seminario.
En esta oportunidad, Liliana Arrachea comentara el paper
``Solid state thermal rectifier''
C. W. Chang et al, Science 314, 1121 (2006)
Abstract
We demonstrated nanoscale solid-state thermal rectification.
High-thermal-conductivity carbon and boron nitride nanotubes were
mass-loaded externally and inhomogeneously with heavy molecules. The
resulting nanoscale system yields asymmetric axial thermal conductance
with greater heat flow in the direction of decreasing mass density.
The effect cannot be explained by ordinary perturbative wave theories,
and instead we suggest that solitons may be responsible for the
phenomenon. Considering the important role of electrical rectifiers
(diodes) in electronics, thermal rectifiers have substantial
implications for diverse thermal management problems, ranging from
nanoscale calorimeters to microelectronic processors to macroscopic
refrigerators and energy-saving buildings
http://www.sciencemag.org/cgi/content/abstract/314/5802/1121
Si hay tiempo, sigue Victoria Bekeris, empieza con
Superconducting Vortices in CeCoIn5: Toward the Pauli-Limiting Field
Volume 319(5860), 11 January 2008, pp 177-180
Many superconducting materials allow the penetration of magnetic
fields in a mixed state in which the superfluid is threaded by a
regular lattice of Abrikosov vortices, each carrying one quantum of
magnetic flux. The phenomenological Ginzburg-Landau theory, based on
the concept of characteristic length scales, has generally provided a
good description of the Abrikosov vortex lattice state. We conducted
neutron-scattering measurements of the vortex lattice form factor in
the heavy-fermion superconductor cerium-cobalt-indium (CeCoIn5) and
found that this form factor increases with increasing field-opposite
to the expectations within the Abrikosov-Ginzburg-Landau paradigm. We
propose that the anomalous field dependence of the form factor arises
from Pauli paramagnetic effects around the vortex cores and from the
proximity of the superconducting state to a quantum critical point.
http://www.sciencemag.org/cgi/reprint/319/5860/177.pdf
TODOS CORDIALEMENTE INVITADOS.
PROPUESTAS PARA NUEVAS LECTURAS SON BIENVENIDAS
Gustavo S Lozano
Depto de Fisica, FCEyN,UBA
PAB I Ciudad Universitaria
1428 Buenos Aires
Argentina
Phone 0054-11-4576 3390 (ext 816)
Phone 0054-11-4576 3353 (Physics Dept)
Fax 0054-11-4576 33577
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