4,474 research outputs found
Klein-Gordon Oscillator in Kaluza-Klein Theory
In this contribution we study the Klein-Gordon oscillator on the curved
background within the Kaluza-Klein theory. The problem of interaction between
particles coupled harmonically with a topological defects in Kaluza-Klein
theory is studied. We consider a series of topological defects, that treat the
Klein-Gordon oscillator coupled to this background and find the energy levels
and corresponding eigenfunctions in these cases. We show that the energy levels
depend on the global parameters characterizing these spacetimes. We also
investigate a quantum particle described by the Klein-Gordon oscillator
interacting with a cosmic dislocation in Som-Raychaudhuri spacetime in the
presence of homogeneous magnetic field in a Kaluza-Klein theory. In this case,
the spectrum of energy is determined, and we observe that these energy levels
are the sum of the term related with Aharonov-Bohm flux and of the parameter
associated to the rotation of the spacetime.Comment: 15 pages, no figur
Aspectos geológicos do Estado do Acre e implicações na evolução da paisagem.
bitstream/item/32345/1/doc104.pd
Zoneamento geológico e geomorfológico entre Feijó e Mâncio Lima: Acre.
Introdução; Metodologia; Geologia da área; Geomorfologia da área; Anexosbitstream/CPAF-AC/15627/1/doc99.pd
Electrostatics of electron-hole interactions in van der Waals heterostructures
The role of dielectric screening of electron-hole interaction in van der
Waals heterostructures is theoretically investigated. A comparison between
models available in the literature for describing these interactions is made
and the limitations of these approaches are discussed. A simple numerical
solution of Poissons equation for a stack of dielectric slabs based on a
transfer matrix method is developed, enabling the calculation of the
electron-hole interaction potential at very low computational cost and with
reasonable accuracy. Using different potential models, direct and indirect
exciton binding energies in these systems are calculated within Wannier-Mott
theory, and a comparison of theoretical results with recent experiments on
excitons in two-dimensional materials is discussed.Comment: 10 pages, 8 figure
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
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