1,942 research outputs found
Anomalous Transmission Phase of a Kondo-Correlated Quantum Dot
We study phase evolution of transmission through a quantum dot with Kondo
correlations. By considering a model that includes nonresonant transmission as
well as the Anderson impurity, we explain unusually large phase evolution of
about in the Kondo valley observed in recent experiments. We argue that
this anomalous phase evolution is a universal property that can be found in the
high-temperature Kondo phase in the presence of the time-reversal symmetry.Comment: 5 pages, 3 figure
Kondo Effect and Josephson Current through a Quantum Dot between Two Superconductors
We investigate the supercurrent through a quantum dot for the whole range of
couplings using the numerical renormalization group method. We find that the
Josephson current switches abruptly from a - to a 0-phase as the coupling
increases. At intermediate couplings the total spin in the ground state depends
on the phase difference between the two superconductors. Our numerical results
can explain the crossover in the conductance observed experimentally by
Buitelaar \textit{et al.} [Phys. Rev. Lett. \textbf{89}, 256 801 (2002)].Comment: Fig.2 and corresponding text have been changed; Several other small
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The Two-impurity Anderson Model Revisited: Competition between Kondo Effect and Reservoir-mediated Superexchange in Double Quantum Dots
We study a series-coupled double quantum dot in the Kondo regime modeled by
the two-impurity Anderson model and find a new conduction-band mediated
superexchange interaction that competes with Kondo physics in the strong
Coulomb interaction limit. Our numerical renormalization group results,
complemented with the higher-order Rayleigh-Schr\"odinger perturbation theory,
show that the novel exchange mechanism leads to clear experimental consequences
that can be checked in transport measurements through double quantum dots
Josephson current in strongly correlated double quantum dots
We study the transport properties of a serial double quantum dot (DQD)
coupled to two superconducting leads, focusing on the Josephson current through
the DQD and the associated 0- transitions which result from the subtle
interplay between the superconductivity, the Kondo physics, and the inter-dot
superexchange interaction. We examine the competition between the
superconductivity and the Kondo physics by tuning the relative strength
of the superconducting gap and the Kondo temperature
, for different strengths of the superexchange coupling determined by the
interdot tunneling relative to the dot level broadening . We find
strong renormalization of , a significant role of the superexchange coupling
, and a rich phase diagram of the 0 and -junction regimes. In
particular, when both the superconductivity and the exchange interaction are in
close competion with the Kondo physics (), there appears
an island of -phase at large values of the superconducting phase
difference.Comment: 4 pages, 4 figure
Generation and characterization of nucleic acid aptamers targeting the capsid P domain of a human norovirus GII.4 strain
AbstractHuman noroviruses (NoV) are the leading cause of acute viral gastroenteritis worldwide. Significant antigenic diversity of NoV strains has limited the availability of broadly reactive ligands for design of detection assays. The purpose of this work was to produce and characterize single stranded (ss)DNA aptamers with binding specificity to human NoV using an easily produced NoV target—the P domain protein. Aptamer selection was done using SELEX (Systematic Evolution of Ligands by EXponential enrichment) directed against an Escherichia coli-expressed and purified epidemic NoV GII.4 strain P domain. Two of six unique aptamers (designated M1 and M6-2) were chosen for characterization. Inclusivity testing using an enzyme-linked aptamer sorbent assay (ELASA) against a panel of 14 virus-like particles (VLPs) showed these aptamers had broad reactivity and exhibited strong binding to GI.7, GII.2, two GII.4 strains, and GII.7 VLPs. Aptamer M6-2 exhibited at least low to moderate binding to all VLPs tested. Aptamers significantly (p<0.05) bound virus in partially purified GII.4 New Orleans outbreak stool specimens as demonstrated by ELASA and aptamer magnetic capture (AMC) followed by RT-qPCR. This is the first demonstration of human NoV P domain protein as a functional target for the selection of nucleic acid aptamers that specifically bind and broadly recognize diverse human NoV strains
Development of Transgenic Tall Fescue Plants with Enhanced Tolerance to Multiple Abiotic Stresses
Kondo-like behaviors in magnetic and thermal properties of single crystal Tm5Si2Ge2
We grew the single crystal of stoichiometric Tm5Si2.0Ge2.0 using a Bridgeman
method and performed XRD, EDS, magnetization, ac and dc magnetic
susceptibilities, specific heat, electrical resistivity and XPS experiments. It
crystallizes in orthorhombic Sm5Ge4-type structure. The mean valence of Tm ions
in Tm5Si2.0Ge2.0 is almost trivalent. The 4f states is split by the crystalline
electric field. The ground state exhibits the long range antiferromagnetic
order with the ferromagnetically coupled magnetic moments in the ac plane below
8.01 K, while the exited states exhibit the reduction of magnetic moment and
magnetic entropy and -log T-behaviors observed in Kondo materials.Comment: 8 pages, 13 figure
Identification of the early and late responder genes during the generation of induced pluripotent stem cells from mouse fibroblasts
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Magnetization dynamics induced by in-plane currents in ultrathin magnetic nanostructures
Ultrathin magnetic systems have properties qualitatively different from their
thicker counterparts, implying that different physics governs their properties.
We demonstrate that various such properties can be explained naturally by the
Rashba spin-orbit coupling in ultrathin magnetic systems. This work will be
valuable for the development of next generation spintronic devices based on
ultrathin magnetic systems.Comment: 4+ pages, 3 figure
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