Quantum Hall Conductivity in a Landau Type Model with a Realistic Geometry

In this paper, we revisit some quantum mechanical aspects related to the Quantum Hall Effect. We consider a Landau type model, paying a special attention to the experimental and geometrical features of Quantum Hall experiments. The resulting formalism is then used to compute explicitely the Hall conductivity from a Kubo formula.Comment: LaTeX, 1 eps figur

Vortex in Maxwell-Chern-Simons models coupled to external backgrounds

We consider Maxwell-Chern-Simons models involving different non-minimal coupling terms to a non relativistic massive scalar and further coupled to an external uniform background charge. We study how these models can be constrained to support static radially symmetric vortex configurations saturating the lower bound for the energy. Models involving Zeeman-type coupling support such vortices provided the potential has a "symmetry breaking" form and a relation between parameters holds. In models where minimal coupling is supplemented by magnetic and electric field dependant coupling terms, non trivial vortex configurations minimizing the energy occur only when a non linear potential is introduced. The corresponding vortices are studied numericallyComment: LaTeX file, 2 figure

Hamiltonians for the Quantum Hall Effect on Spaces with Non-Constant Metrics

The problem of studying the quantum Hall effect on manifolds with nonconstant metric is addressed. The Hamiltonian on a space with hyperbolic metric is determined, and the spectrum and eigenfunctions are calculated in closed form. The hyperbolic disk is also considered and some other applications of this approach are discussed as well.Comment: 16 page

Global quantum Hall phase diagram from visibility diagrams

We propose a construction of a global phase diagram for the quantum Hall effect. This global phase diagram is based on our previous constructions of visibility diagrams in the context of the Quantum Hall Effect. The topology of the phase diagram we obtain is in good agreement with experimental observations (when the spin effect can be neglected). This phase diagram does not show floating.Comment: LaTeX2e, 9 pages, 5 eps figure

Self-duality in Maxwell-Chern-Simons type effective theories

We consider a class of (2+1)-dimensional nonlocal effective models with a MaxwellChern-Simons part for which the Maxwell term involves a suitable nonlocality that permits one to take into account some (3+1)-dimensional features of "real" planar systems. We show that this class of models exhibits a hidden duality symmetry stemming from the Maxwell-Chern-Simons part of the action. We discuss and illustrate this result in the framework of a (2+1)-dimensional effective model describing (massive) vortices and charges with realistic interactions

A comparative study of embryogenic and non-embryogenic cell cultures in Picea abies (L.) Karst.

Embryogenic cell cultures (or ESMs’,for embryonal-suspensor masses) and non embryogenic cultures (or ‘NEC’ for non embryogenic calli) have been initiated from young cotyledons in Picea abies (L.) Karst and separately multiplied for over two years. In order to better understand their physiological peculiarities, two molecular approaches were followed. First, bidimensional electrophoreses were used for comparing the polypeptide patterns in ESMs and NEC. Multiple extracellular polypeptides appeared specific to the embryogenic cell cultures, while several intracellular polypeptides were only observed in the non embryogenic calli, cultivated in the light or in darkness. Second, a mitochondrial DNA library was constructed in Picea abies and 168plasmid clones were used as RFLP probes for comparing the structure of the mitochondrial genome in the two types of cell material. Two probes detected extensive and qualitative DNA polymorphisms between embryogenic and non embryogenic cell cultures. Interestingly, the mtDNA pattern in ESMs was distinct from that of the corresponding mother plants (as defined in buds and needles), but apparent reversion to the mother plant pattern was observed upon embryo maturation. When comparing ESMs or NEC between genotypes, the two mtDNA probes detected extensive polymorphism, while the protein markers seemed to be genotype-independent