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Transport in the metallic regime of Mn doped III-V Semiconductors
The standard model of Mn doping in GaAs is subjected to a coherent potential
approximation (CPA) treatment. Transport coefficients are evaluated within the
linear response Kubo formalism. Both normal (NHE) and anomalous contributions
(AHE) to the Hall effect are examined. We use a simple model density of states
to describe the undoped valence band. The CPA bandstructure evolves into a spin
split band caused by the exchange scattering with Mn dopants. This gives
rise to a strong magnetoresistance, which decreases sharply with temperature.
The temperature () dependence of the resistance is due to spin disorder
scattering (increasing with ), CPA bandstructure renormalization and charged
impurity scattering (decreasing with ). The calculated transport
coefficients are discussed in relation to experiment, with a view of assessing
the overall trends and deciding whether the model describes the right physics.
This does indeed appear to be case, bearing in mind that the hopping limit
needs to be treated separately, as it cannot be described within the band CPA.Comment: submitted to Phys. Rev.
Brown v. ABF Freight Systems, Inc.
Published in cooperation with the American Bar Association Section of Dispute Resolutio
Alien Registration- Arsenault, Mary A. (Old Town, Penobscot County)
https://digitalmaine.com/alien_docs/7787/thumbnail.jp
Benchmark of a modified Iterated Perturbation Theory approach on the 3d FCC lattice at strong coupling
The Dynamical Mean-Field theory (DMFT) approach to the Hubbard model requires
a method to solve the problem of a quantum impurity in a bath of
non-interacting electrons. Iterated Perturbation Theory (IPT) has proven its
effectiveness as a solver in many cases of interest. Based on general
principles and on comparisons with an essentially exact Continuous-Time Quantum
Monte Carlo (CTQMC) solver, here we show that the standard implementation of
IPT fails away from half-filling when the interaction strength is much larger
than the bandwidth. We propose a slight modification to the IPT algorithm that
replaces one of the equations by the requirement that double occupancy
calculated with IPT gives the correct value. We call this method IPT-. We
recover the Fermi liquid ground state away from half-filling. The Fermi liquid
parameters, density of states, chemical potential, energy and specific heat on
the FCC lattice are calculated with both IPT- and CTQMC as benchmark
examples. We also calculated the resistivity and the optical conductivity
within IPT-. Particle-hole asymmetry persists even at coupling twice the
bandwidth. Several algorithms that speed up the calculations are described in
appendices.Comment: 17 pages, 15 figures, minor changes to improve clarit
Cleaved intracellular SNARE peptides are implicated in a novel cytotoxicity mechanism of botulinum serotype C
Recent advances in intracellular protein delivery have enabled more in-depth analyses of
cellular functions. A specialized family of SNARE proteases, known as Botulinum
Neurotoxins, blocks neurotransmitter exocytosis, which leads to systemic toxicity caused by
flaccid paralysis. These pharmaceutically valuable enzymes have also been helpful in the
study of SNARE functions. As can be seen in Figure 1A, SNARE bundle formation causes
vesicle docking at the presynapse. Although these toxins are systemically toxic, no known
cytotoxic effects have been reported with the curious exception of the Botulinum serotype C
[1]. This enzyme cleaves intracellular SNAP25, as does serotype A and E, but also,
exceptionally, cleaves Syntaxin 1. Using an array of lipid and polymer transfection reagents
we were able to deliver different combinations of Botulinum holoenzymes into the normally
unaffected, Neuro2A, SH-SY5Y, PC12, and Min6 cells to analyze the individual
contribution of each SNARE protein and their cleaved peptide products
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