6,248 research outputs found
Forbidden island heights in stress-driven coherent Stranski-Krastanov growth
The observed height distribution of clusters obtained in strained epitaxy has
been often interpreted in terms of electronic effects. We show that some
aspects can be explained classically by the interplay of strain and edge
energies. We find that soft materials can transform directly from monolayer
into thicker islands by two-dimensional (2D) multilayer nucleation and growth.
There is a critical thickness decreasing with the force constant. Thinner
islands are thermodynamically forbidden, due to the insufficient stress
relaxation upon clustering particularly under tensile stress. At sufficiently
large misfits the barrier for 2D multilayer nucleation is significantly smaller
than the barrier for subsequent single-layer nucleation. The effects are found
to be quantitatively reasonable and offer a plausible explanation for the
absence of thin islands and 2D growth of flattop islands usually attributed to
quantum size effects.Comment: 4 pages, 4 figures. Accepted version. Includes quantitative
estimations comparing with experiments plus minor change
Higgs bundles over elliptic curves
In this paper we study -Higgs bundles over an elliptic curve when the
structure group is a classical complex reductive Lie group. Modifying the
notion of family, we define a new moduli problem for the classification of
semistable -Higgs bundles of a given topological type over an elliptic curve
and we give an explicit description of the associated moduli space as a finite
quotient of a product of copies of the cotangent bundle of the elliptic curve.
We construct a bijective morphism from this new moduli space to the usual
moduli space of semistable -Higgs bundles, proving that the former is the
normalization of the latter. We also obtain an explicit description of the
Hitchin fibration for our (new) moduli space of -Higgs bundles and we study
the generic and non-generic fibres
Hamevol1.0: a C++ code for differential equations based on Runge-Kutta algorithm. An application to matter enhanced neutrino oscillation
We present a C++ implementation of a fifth order semi-implicit Runge-Kutta
algorithm for solving Ordinary Differential Equations. This algorithm can be
used for studying many different problems and in particular it can be applied
for computing the evolution of any system whose Hamiltonian is known. We
consider in particular the problem of calculating the neutrino oscillation
probabilities in presence of matter interactions. The time performance and the
accuracy of this implementation is competitive with respect to the other
analytical and numerical techniques used in literature. The algorithm design
and the salient features of the code are presented and discussed and some
explicit examples of code application are given.Comment: 18 pages, Late
Generating and verifying graph states for fault-tolerant topological measurement-based quantum computing in 2D optical lattices
We propose two schemes for implementing graph states useful for
fault-tolerant topological measurement-based quantum computation in 2D optical
lattices. We show that bilayer cluster and surface code states can be created
by global single-row and controlled-Z operations. The schemes benefit from the
accessibility of atom addressing on 2D optical lattices and the existence of an
efficient verification protocol which allows us to ensure the experimental
feasibility of measuring the fidelity of the system against the ideal graph
state. The simulation results show potential for a physical realization toward
fault-tolerant measurement-based quantum computation against dephasing and
unitary phase errors in optical lattices.Comment: 6 pages and 4 figures (minor changed
Characterization of a novel human CAP2 interacting protein: Neuronal calcium binding protein 1 (Necab1).
The actin cytoskeleton is implicated in numerous processes such as cellular division, migration, endocytosislexocytosis, and more recently synaptic plasticity. Important players in controlling cytoskeletal rearrangements are the Cyclase Associated Proteins (CAPs) which are thought to link cell signalling to the dynamics of the actin cytoskeleton, via sequestration of monomeric actin subunits. CAPs are conserved throughout evolution and possess conserved functional domains. Previous studies have suggested a link between CAP proteins and vesicle trafficking and this study focussed on characterizing binding partners of human CAPs. Using a two hybrid screen of a human adult brain cDNA library, a novel human CAP interacting protein named Neuronal calcium binding protein 1 (Necab1) has been isolated. Necab1 is a 351 amino acid protein containing a predicted calcium binding EF-hand and three coiled-coil domains. It is highly expressed in human brain, and similar to CAP2, displays high levels of expression within the hippocampus and cerebral cortex of rat brain. In vitro binding and in vivo immunoprecipitations demonstrate that CAP2 interacts with Necab1. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .M68. Source: Masters Abstracts International, Volume: 43-01, page: 0215. Adviser: A. V. Hubberstey. Thesis (M.Sc.)--University of Windsor (Canada), 2003
- …