7,762 research outputs found
Pseudogap and the specific heat of high superconductors
The specific heat of a two dimensional repulsive Hubbard model with local
interaction is investigated. We use the two-pole approximation which exhibits
explicitly important correlations that are sources of the pseudogap anomaly.
The interplay between the specific heat and the pseudogap is the main focus of
the present work. Our self consistent numerical results show that above the
occupation , the specific heat starts to decrease due to the
presence of a pseudogap in the density of states. We have also observed a two
peak structure in the specific heat. Such structure is robust with respect to
the Coulomb interaction but it is significantly affected by the occupation
. A detailed study of the two peak structure is carried out in terms of
the renormalized quasi-particle bands. The role of the second nearest neighbor
hopping on the specific heat behavior and on the pseudogap, is extensively
discussed.Comment: 6 pages, 6 figures, accepted for publication in Solid State
Communication
Bound vortex states and exotic lattices in multi-component Bose-Einstein condensates: The role of vortex-vortex interaction
We numerically study the vortex-vortex interaction in multi-component
homogeneous Bose-Einstein condensates within the realm of the Gross-Pitaevskii
theory. We provide strong evidences that pairwise vortex interaction captures
the underlying mechanisms which determine the geometric configuration of the
vortices, such as different lattices in many-vortex states, as well as the
bound vortex states with two (dimer) or three (trimer) vortices. Specifically,
we discuss and apply our theoretical approach to investigate intra- and
inter-component vortex-vortex interactions in two- and three-component
Bose-Einstein condensates, thereby shedding light on the formation of the
exotic vortex configurations. These results correlate with current experimental
efforts in multi-component Bose-Einstein condensates, and the understanding of
the role of vortex interactions in multiband superconductors.Comment: Published in PR
All-strain based valley filter in graphene nanoribbons using snake states
A pseudo-magnetic field kink can be realized along a graphene nanoribbon
using strain engineering. Electron transport along this kink is governed by
snake states that are characterized by a single propagation direction. Those
pseudo-magnetic fields point towards opposite directions in the K and K'
valleys, leading to valley polarized snake states. In a graphene nanoribbon
with armchair edges this effect results in a valley filter that is based only
on strain engineering. We discuss how to maximize this valley filtering by
adjusting the parameters that define the stress distribution along the graphene
ribbon.Comment: 8 pages, 6 figure
Microfenótipos e proteínas associados à expressão da resistência durável à ferrugem da folha do trigo.
Editores técnicos: Joseani Mesquita Antunes, Ana Lídia Variani Bonato, Márcia Barrocas Moreira Pimentel
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