Author
S. Roth
Bio: S. Roth is an academic researcher from Max Planck Society. The author has contributed to research in topics: Carbon nanotube & Polyacetylene. The author has an hindex of 44, co-authored 281 publications receiving 25195 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this article, a bilayer sandwich structure was fabricated by the sequential thermal evaporation of gold, copper phthalocyanine (CuPc), C60 and gold onto sapphire substrates.
Abstract: Bilayer sandwich structures were fabricated by the sequential thermal evaporation of gold, copper phthalocyanine (CuPc), C60 and gold onto sapphire substrates. When the current—voltage characteristics of a freshly made device are measured in an atmosphere of argon, fairly strong rectification is observed. When the bilayer device is exposed to ammonia vapor, the rectification slowly decreases and almost disappears. If the device is then placed under vacuum and the ammonia removed, the initial conditions slowly return. We attribute the rectification to the formation of a p—n junction. PACS numbers: 73.40.—c, 73.40.Ei, 73.61.Ph
2 citations
TL;DR: In this article, the dark conductivity and photoconductivity on organic tunnel junctions were measured using the Langmuir-Blodgett technique, and it was shown that both organic layers in the tunnel junction are intact.
2 citations
Journal Article•
TL;DR: In this article, the de Haas-van Alphen torque method was used to measure the oscillatory magnetization of graphite compounds in a cyclotron in fields up to 22 T. Despite this fact the wave form of the oscillations is perfect sinusoidal in contrast to the standard theory, it was found that the Fermi surface is ideally cylindrical.
Abstract: The oscillatory magnetization of stage 1 and 2 AsF5 intercalated graphite compounds was measured with the de Haas-van Alphen torque method in fields up to 22 T. From the angular dependence of the de Haas-van Alphen frequency and the cyclotron effective mass we conclude that the Fermi surface is ideally cylindrical. The Landau levels are found to be well separated compared with the broadening due to imperfections. Despite this fact the wave form of the oscillations is perfect sinusoidal in contrast to the standard theory.
2 citations
TL;DR: The thermopower of highly conductive oriented polyacetylene doped with iodine was measured and the maximum conductivity at room temperature of these samples was about 2 × 10 4 S/cm.
2 citations
01 Jan 2004
TL;DR: In this paper, the effect of noncovalent interaction of carbon single-walled nanotubes with organic molecules and surfactants of different types on optical spectra is discussed.
Abstract: Raman spectra of film HiPCO carbon single-walled nanotubes (SWNTs) with organic molecules (pyrene, naphthalene) and nanotubes aqueous solutions with different type surfactants are studied. In the spectra of these complex systems the spectral shift of the line position and intensity redistribution among the lines, compared with the spectra of pristine SWNT in KBr pellet or film, is observed that indicates interaction between nanotubes and molecules. Influence of different type surfactants on visible-near-infra-red absorption spectra of SWNTs in water solutions is investigated. The most essential spectral changes are observed for nanotube with the surfactant containing a charge group. Effect of noncovalent interaction of SWNTs with organic molecules and surfactants of different types on optical spectra is discussed.
2 citations
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TL;DR: Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena can now be mimicked and tested in table-top experiments.
Abstract: Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when commercial products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top experiments. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.
35,293 citations
TL;DR: In this paper, the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations, are discussed.
Abstract: This article reviews the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations. The Dirac electrons can be controlled by application of external electric and magnetic fields, or by altering sample geometry and/or topology. The Dirac electrons behave in unusual ways in tunneling, confinement, and the integer quantum Hall effect. The electronic properties of graphene stacks are discussed and vary with stacking order and number of layers. Edge (surface) states in graphene depend on the edge termination (zigzag or armchair) and affect the physical properties of nanoribbons. Different types of disorder modify the Dirac equation leading to unusual spectroscopic and transport properties. The effects of electron-electron and electron-phonon interactions in single layer and multilayer graphene are also presented.
20,824 citations
28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组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�ly.
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。
18,940 citations
TL;DR: Graphene is established as the strongest material ever measured, and atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.
Abstract: We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an atomic force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per meter (N m(-1)) and -690 Nm(-1), respectively. The breaking strength is 42 N m(-1) and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of sigma(int) = 130 gigapascals for bulk graphite. These experiments establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.
18,008 citations
TL;DR: This review analyzes recent trends in graphene research and applications, and attempts to identify future directions in which the field is likely to develop.
Abstract: Graphene is a wonder material with many superlatives to its name. It is the thinnest known material in the universe and the strongest ever measured. Its charge carriers exhibit giant intrinsic mobility, have zero effective mass, and can travel for micrometers without scattering at room temperature. Graphene can sustain current densities six orders of magnitude higher than that of copper, shows record thermal conductivity and stiffness, is impermeable to gases, and reconciles such conflicting qualities as brittleness and ductility. Electron transport in graphene is described by a Dirac-like equation, which allows the investigation of relativistic quantum phenomena in a benchtop experiment. This review analyzes recent trends in graphene research and applications, and attempts to identify future directions in which the field is likely to develop.
12,117 citations