3,719 research outputs found
Thermoelectric effects in graphene with local spin-orbit interaction
We investigate the transport properties of a graphene layer in the presence
of Rashba spin-orbit interaction. Quite generally, spin-orbit interactions
induce spin splittings and modifications of the graphene bandstructure. We
calculate within the scattering approach the linear electric and thermoelectric
responses of a clean sample when the Rashba coupling is localized around a
finite region. We find that the thermoelectric conductance, unlike its electric
counterpart, is quite sensitive to external modulations of the Fermi energy.
Therefore, our results suggest that thermocurrent measurements may serve as a
useful tool to detect nonhomogeneous spin-orbit interactions present in a
graphene-based device. Furthermore, we find that the junction thermopower is
largely dominated by an intrinsic term independently of the spin-orbit
potential scattering. We discuss the possibility of cancelling the intrinsic
thermopower by resolving the Seebeck coefficient in the subband space. This
causes unbalanced populations of electronic modes which can be tuned with
external gate voltages or applied temperature biases.Comment: 9 pages, 8 figures. The Eq.(27) and the definition of charge
thermopower have been correcte
Financial Intermediation in Muslim Community: Issues and Problems
It is widely known that Muslim society inherited an interest based financial intermediation system from others instead of developing their own banking system. However, Muslim Economists and scholars around the world made efforts to have and develop their own financial intermediation since there was no initial working model to act upon, except the belief that interest-based financial intermediation might be replaced by an Islamic one on the basis of profit-and loss sharing. During the last four decades, Islamic financial intermediation industry became a reality that the Muslim society around the world can see and practice. However, the Islamic financial intermediation in the world has been facing numerous problems of challenges. It raises a number of issues and potential problems which can be seen from the macro and micro operational point of view. Developing the Islamic financial intermediation depends on clarifying these issues and presenting them in order to focus on them studying and remedying. This paper aims to cover the ground of issues of Islamic financial intermediation that rose during its short age. Such issues prevent Islamic financial intermediation from its operating with its full efficiency level. Even no attempt to remedy these issues, presenting these issues and problems and classifying them according to their type is very valuable for sustained growth and development of the Islamic financial intermediation. Such work is a valuable contribution to build the Islamic financial intermediation industry on sound theoretical foundations.
Coulomb-blockade effect in nonlinear mesoscopic capacitors
We consider an interacting quantum dot working as a coherent source of single
electrons. The dot is tunnel coupled to a reservoir and capacitively coupled to
a gate terminal with an applied ac potential. At low frequencies, this is the
quantum analog of the RC circuit with a purely dynamical response. We
investigate the quantized dynamics as a consequence of ac pulses with large
amplitude. Within a Keldysh-Green function formalism we derive the
time-dependent current in the Coulomb blockade regime. Our theory thus extends
previous models that considered either noninteracting electrons in nonlinear
response or interacting electrons in the linear regime. We prove that the
electron emission and absorption resonances undergo a splitting when the
charging energy is larger than the tunnel broadening. For very large charging
energies, the additional peaks collapse and the original resonances are
recovered, though with a reduced amplitude. Quantization of the charge emitted
by the capacitor is reduced due to Coulomb repulsion and additional plateaus
arise. Additionally, we discuss the differential capacitance and resistance as
a function of time. We find that to leading order in driving frequency the
current can be expressed as a weighted sum of noninteracting currents shifted
by the charging energy.Comment: 13 pages, 9 figures. Minor changes. Published versio
El casco medieval de Palma de Mallorca como problema y como realidad urbanística positiva : estudio de su tratamiento en el plan Ribas-Piera
Zoning and the Law of Nuisance
We calculate density and current spatial distributions of a 2D model junction between a normal QAH contact and a superconducting QAH region hosting propagating (chiral) Majorana modes. We use a simplified Hamiltonian describing the spatial coupling of the modes on each side of the junction, as well as the related junction conductance. We study how this coupling is affected by orbital effects caused by an external magnetic field.This work was funded by MINEICO-Spain, grant MAT2017-82639
El treball amb suport de joves amb discapacitat intel.lectual: aportacions a partir d'una recerca
Un precedente olvidado de la futura Universidad Balear: La Universidad de Montpeller : institucionalizada en 1289 bajo el reinado de Jaime II de Mallorca
Abstract not availabl
Apunts sobre la flora del Parc Natural de S'Albufera de Mallorca
Es presenten 120 taxons nous per a la flora de S'Albufera de Mallorca, incrementant-se, doncs, el Catàleg de LLORENS (1980) en un 30% (fins a 552 taxons). Aquesta gran riquesa específica suposa més d'1/3 de la Flora de Mallorca. Matricharia recutita L. i els híbrids Orchis palustris Jacq. X O. coriophora L. i Ophrys X pseudofusca Albert i Cam. (Ophrys fusca Link. X O. incubacea Bianca) són novetats per a la Flora Balear. S'exclou Cistus incanus L. de la Flora de Mallorca. Per altra banda, es relacionen una sèrie de taxons, considerats en regressió.One hundred twenty new records are listed for the flora of S'Albufera de Mallorca. The catalogue by LLORENS (1980) is enlarged by 30% (552 taxa). This great species richness represents over one third of the flora of Majorca. Matricaria recutica L. and the hybrids Orchis palustris Jacq x O. coriophora L. and Ophrys X pseudofusca Albert & Cam. (0. fusca Link x Ophrys incubacea Bianca) are new for the Balearics. Cistus incanus L. is excluded from the Majorcan Flora. Other taxa are listed as undergoing regression
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