E. I. Buchstab

Bio: E. I. Buchstab is an academic researcher from Technion – Israel Institute of Technology. The author has contributed to research in topics: Superconductivity & Josephson effect. The author has an hindex of 9, co-authored 22 publications receiving 980 citations.

DNA-Templated Carbon Nanotube Field-Effect Transistor

Abstract: The combination of their electronic properties and dimensions makes carbon nanotubes ideal building blocks for molecular electronics. However, the advancement of carbon nanotube-based electronics requires assembly strategies that allow their precise localization and interconnection. Using a scheme based on recognition between molecular building blocks, we report the realization of a self-assembled carbon nanotube field-effect transistor operating at room temperature. A DNA scaffold molecule provides the address for precise localization of a semiconducting single-wall carbon nanotube as well as the template for the extended metallic wires contacting it.

Thermodynamics of a Charged Fermion Layer at High r s Values

Abstract: The chemical potential $\ensuremath{\mu}$ of a hole layer is mapped as a function of temperature and density $p$. We present the first investigation of the crossover from the strongly interacting degenerate regime to the classical ideal gas limit. The low temperature inverse compressibility, ${\ensuremath{\kappa}}^{\ensuremath{-}1}\ensuremath{\equiv}{p}^{2}\ensuremath{\partial}\ensuremath{\mu}/\ensuremath{\partial}p$, is negative and temperature independent. At $T\ensuremath{\approx}17\mathrm{K}$ temperature dependence commences abruptly: ${\ensuremath{\kappa}}^{\ensuremath{-}1}$ turns less negative with rising $T$ and eventually reverses sign. An ideal classical gas is attained at temperatures comparable to the interaction energy, more than an order of magnitude larger than the Fermi energy.

Interfacial superconductivity in semiconducting monochalcogenide superlattices

Abstract: Superconducting and structural properties of superconducting semiconducting multilayers are investigated. These layered systems are obtained by epitaxial growth of the isomorphic monochalcogenides of Pb, Sn, and rare-earth elements on a KCl substrate. Some of these compounds are narrow-gap semiconductors (PbTe, PbS, PbSe, SnTe). Layered structures containing one or two narrow-gap semiconductors have a metallic type of conductivity and a transition to a superconducting state at temperatures in the range of 2.5–6 K. Structures containing only wide-gap semiconductors (YbS, EuS, EuSe) do not demonstrate such properties. All superconducting layered systems are type-II superconductors. The critical magnetic fields and the resistive behavior in the mixed state reveal features characteristic of other layered superconductors. However, data obtained in magnetic fields testify that the period of the superstructure corresponds to half of that obtained from x-ray-diffractometry investigations. This is evidence that the superconducting layers in these samples are confined to the interfaces between two semiconductors. Electron microscopy studies reveal that in the case of epitaxial growth the interfaces contain regular grids of misfit dislocations covering all the interface area. These samples appear to undergo a superconducting transition if they have a metallic type of conductivity in the normal state. Samples with island-type dislocation grids only reveal partial superconducting transitions. The correlations between the appearance of superconductivity and the presence of dislocations, which have been found experimentally, lead to the conclusion that the normal metallic conductivity as well as the superconductivity are induced by the elastic deformation fields created by the misfit dislocation grids. A theoretical model is proposed for the description of the narrow-gap semiconductor metallization, which is due to a band inversion effect and the appearance of electron- or hole-type inversion layers near the interfaces. For different combinations of the semiconductors, such inversion layers in the superlattices can have different shapes and topology. In particular, they can form multiply connected periodic nets having a repetition period coinciding with that of the dislocation grids. Numerical estimates show that such a scenario for the appearance of superconductivity is quite likely. It is shown that the new type of metallic and superconducting nanoscale two-dimensional structures with unusual properties may be obtained from monochalcogenide semiconductors.

Direct evidence for interfacial superconductivity in two-layer semiconducting heterostructures

Abstract: We have discovered superconductivity in the two-layer semiconducting monochalcogenide heterostrutures $\mathrm{Pb}\mathrm{Te}∕\mathrm{Pb}\mathrm{S}$, $\mathrm{Pb}\mathrm{Te}∕\mathrm{Pb}\mathrm{Se}$ and $\mathrm{Pb}\mathrm{Te}∕\mathrm{Yb}\mathrm{S}$. By comparing data from two-layer samples with data from single monochalcogenide films we conclude that the superconductivity is connected with the interface between the two semiconductors. Evidence for the low dimensional nature of the superconducting interlayer is presented and a model that explains the appearance of single-interface superconductivity is proposed.

Interband scattering and the "Metallic Phase" of two-dimensional holes in GaAs /AlGaAs

Abstract: The "metallic" characteristics of high density holes in GaAs/AlGaAs heterostructures are attributed to inelastic scattering between the two split heavy hole bands. Landau fan diagrams and weak field magnetoresistance are employed to measure the interband scattering rate. The inelastic rate is found to depend on temperature with an activation energy similar to that characterizing the longitudinal resistance. It is argued that acoustic plasmon mediated Coulomb scattering might be responsible for the Arrhenius dependence on temperature. The absence of standard Coulomb scattering characterized by a power-law dependence upon temperature is pointed out.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Chemistry of Carbon Nanotubes

Abstract: Department of Materials Science, University of Patras, 26504 Rio Patras, Greece, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Avenue, 116 35 Athens, Greece, Institut de Biologie Moleculaire et Cellulaire, UPR9021 CNRS, Immunologie et Chimie Therapeutiques, 67084 Strasbourg, France, and Dipartimento di Scienze Farmaceutiche, Universita di Trieste, Piazzale Europa 1, 34127 Trieste, Italy

Applications of nanoparticles in biology and medicine

Abstract: Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. Their unique size-dependent properties make these materials superior and indispensable in many areas of human activity. This brief review tries to summarise the most recent developments in the field of applied nanomaterials, in particular their application in biology and medicine, and discusses their commercialisation prospects.

High-performance lithium-ion anodes using a hierarchical bottom-up approach

Abstract: Si-based Li-ion battery anodes have recently received great attention, as they offer specific capacity an order of magnitude beyond that of conventional graphite. The applications of this transformative technology require synthesis routes capable of producing safe and easy-to-handle anode particles with low volume changes and stable performance during battery operation. Herein, we report a large-scale hierarchical bottom-up assembly route for the formation of Si on the nanoscale--containing rigid and robust spheres with irregular channels for rapid access of Li ions into the particle bulk. Large Si volume changes on Li insertion and extraction are accommodated by the particle's internal porosity. Reversible capacities over five times higher than that of the state-of-the-art anodes (1,950 mA h g(-1)) and stable performance are attained. The synthesis process is simple, low-cost, safe and broadly applicable, providing new avenues for the rational engineering of electrode materials with enhanced conductivity and power.

Observation of electron–hole puddles in graphene using a scanning single-electron transistor

Abstract: The electronic structure of graphene causes its charge carriers to behave like relativistic particles. For a perfect graphene sheet free from impurities and disorder, the Fermi energy lies at the so-called ‘Dirac point’, where the density of electronic states vanishes. But in the inevitable presence of disorder, theory predicts that equally probable regions of electron-rich and hole-rich puddles will arise. These puddles could explain graphene’s anomalous non-zero minimal conductivity at zero average carrier density. Here, we use a scanning single-electron transistor to map the local density of states and the carrier density landscape in the vicinity of the neutrality point. Our results confirm the existence of electron–hole puddles, and rule out extrinsic substrate effects as explanations for their emergence and topology. Moreover, we find that, unlike non-relativistic particles the density of states can be quantitatively accounted for by considering non-interacting electrons and holes.