Subject: [Depfis] CLUB DE MATERIA CONDENSADA HOY 13.30

From: Gustavo S Lozano <[email-masked]>
Date: Fri, 09 May 2008 11:06:35 -0300

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