Title
Partial pseudospin polarization, latticetronics and Fano resonances in quantum dots based in graphene ribbons: a conductance spectroscopy
Date Issued
01 November 2015
Access level
metadata only access
Resource Type
journal article
Author(s)
Champi A.
Ujevic S.
Mendoza M.
Universidade Federal do ABC
Publisher(s)
springer berlin
Abstract
In this work we study, as a function of the height V and width Lb of the potentialbarriers, the transport of Dirac quasi-particles through quantum dots in graphene ribbons.We observed, as we increase V, a partial polarization (PP) of the pseudospin due to the participation of the hyperbolic bands. This generates polarizations in the sub-lattices A or B outside the dot regions for single, coupled, and open dots. Thus for energies around the Dirac point, the conductance G at both sides of the dot shows a latticetronics of conductances GA and GB as a function ofV and Lb. This fact can be used as a PPspectroscopy which associates hole-type waves with the latticetronics. A periodic enhancement of PP is obtained with the increase of V in dots formed bybarriers that completely occupy the nanoribbon width. For this case, a direct correspondence between G(V) and PP(V) exists. On the other hand, for the open dots, the PP(V) and the G(V) show a complex behavior that exhibit higher intensities when compared to the previous case. In the Dirac limit we have no backscattering signs, however when we move slightly away from this limit the firstsigns of confinement appear in the PP(V) (it freezes in a given sub-lattice). In the last case the backscattering fingerprints are obtained directly fromthe conductance (splittings). The open quantum dots are very sensible to their opening wd and this generatesFano line-shapes of difficult interpretation around the Dirac point. The PP spectroscopy used here allows us to understand the influence of wd in the relativistic analogues and to associate electron-type waves with the observed Fano line-shapes.
Start page
1
End page
11
Volume
88
Issue
11
Language
English
OCDE Knowledge area
Nano-tecnología Física y Astronomía
Scopus EID
2-s2.0-84947232284
Source
European Physical Journal B
ISSN of the container
14346028
Sources of information: Directorio de Producción Científica Scopus