in this research, the effect of the first order magnetic field on the ground-state of a centered hydrogenic donor impurity in a gaas/alas spherical quantum dot has been calculated. the perturbation method has been used within the framework of effective mass approximation for these calculations. overall, the analysis shows that a proper choice of quantum dot radius and magnetic field can signifi...

We report on the observation of periodic conductance oscillations near quantum Hall plateaus in suspended graphene nanoribbons. They are attributed to single quantum dots that are formed in the narrowest part of the ribbon, in the valleys and hills of a disorder potential. In a wide flake with two gates, a double-dot system's signature has been observed. Electrostatic confinement is enabled in ...

The scope of this thesis is the coherence of spins in carbon-based nanodevices. The motivation for this study are the promising spin-related properties of carbon-based materials, such as weak spin-orbit and hyperfine interaction, which are advantageous for achieving long spin coherence times. In addition, carbon based materials such as graphene and carbon nanotubes have a low mass density and h...

D. A. Bahamon,1,* Zenan Qi,2 Harold S. Park,2 Vitor M. Pereira,3,4 and David K. Campbell5 1MackGraphe—Graphene and Nano-Materials Research Center, Mackenzie Presbyterian University, Rua da Consolação 896, 01302-907, São Paulo, SP, Brazil 2Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA 3Centre for Advanced 2D Materials & Graphene Research Centre, Nation...

Open quantum dots provide a window into the connection between quantum and classical physics, particularly through the decoherence theory, in which an important set of quantum states are not “washed out” through interaction with the environment—the pointer states provide connection to trapped classical orbits which remain stable in the dots. Graphene is a recently discovered material with highl...

a noninteracting quantum-dot arrays side coupled to a quantum wire is studied. transport through the quantum wire is investigated by using a noninteracting anderson tunneling hamiltonian. the conductance at zero temperature develops an oscillating band with resonances and antiresonances due to constructive and destructive interference in the ballistic channel, respectively. moreover, we have fo...

Veratryl alcohol can be oxidized to veratryl aldehyde or veratric acid with excellent selectivity and efficient conversion under acidic and alkaline conditions using Au nanoparticles and graphene quantum dot composites (Au/GQDs) as catalysts.

We demonstrate theoretically that quantum dots in bilayers of graphene can be realized. A position-dependent doping breaks the equivalence between the upper and lower layer and lifts the degeneracy of the positive and negative momentum states of the dot. Numerical results show the simultaneous presence of electron and hole confined states for certain doping profiles and a remarkable angular mom...

Utilizing rectangular graphene quantum dots with zigzag horizontal boundaries as a paradigm, we find that the conductance of the dots can exhibit significant oscillations with the position of the leads. The oscillation patterns are a result of quantum interference determined by the band structure of the underlying graphene nanoribbon. In particular, the power spectrum of the conductance variati...