Scanning tunneling spectroscopy

About: Scanning tunneling spectroscopy is a research topic. Over the lifetime, 7886 publications have been published within this topic receiving 213828 citations.

Scanning tunneling microscopy studies of formaldehyde synthesis on Cu(110).

Abstract: The synthesis of formaldehyde from methanol on oxygen-predosed Cu(110) surfaces has been studied using scanning tunneling microscopy (STM). Sequential STM images show the shrinking of the (2\ifmmode\times\else\texttimes\fi{}1) Cu-O islands in the [001] direction and the formation of a (5\ifmmode\times\else\texttimes\fi{}2) methoxy-induced reconstruction that incorporates the added-row Cu atoms of the (2\ifmmode\times\else\texttimes\fi{}1) reconstruction. The decomposition of methoxy to formaldehyde occurs upon desorption; STM images show methoxy islands shrinking in the [001] direction and the release of incorporated Cu atoms.

Single-electron tunneling observed with point-contact tunnel junctions.

Abstract: We have studied the low-temperature tunneling behavior of point-contact junctions with adjustable capacitances in the ${10}^{\ensuremath{-}18}$-F range. The tunneling characteristics show clear evidence of single-electron tunneling, induced by a Coulomb blockade, and are in quantitative agreement with theoretical predictions.

Electronic structure at carbon nanotube tips

Abstract: We discuss a number of recent observations on carbon nanotubes tips. Evidence from scanning tunneling microscopy (STM) and spectroscopy (STS) experiments [1] indicates that the topology of the carbon bond network at the tip, and in particular the relative location of pentagons in the curved regions of the caps, is ultimately responsible for the space-resolved electronic properties of the tubes. The theoretical analysis of the local density of (electronic) states (LDOS) is shown to be a powerful tool to rationalize the experimental data. Images of carbon nanotube tips acquired in field emission microscopy (FEM) experiments [2] can be related to the STM/STS observations.

Reconstruction of the GaAs (311)A surface.

Abstract: We study the reconstruction of the GaAs (311)A surface with reflection high-energy electron-diffraction (RHEED) and scanning tunneling microscopy (STM). The surface observed in situ with RHEED during molecular-beam epitaxy is distinguished by a lateral periodicity of 3.2 nm perpendicular to the [2\ifmmode\bar\else\textasciimacron\fi{}33] direction. This periodicity is confirmed employing in situ STM. High-resolution STM images furthermore reveal a surface reconstruction characterized by a dimerization of the surface As atoms. We show how the reconstruction can be formed, applying a simple electron-counting model. The excellent agreement with the experimental results further support this model, which was already found to explain the reconstructions of the (100) and the (111) surfaces. In order to form a semiconducting surface, the three uppermost layers are involved in the reconstruction process, giving rise to a depth modulation of 0.34 nm.

Prediction of Triple Point Fermions in Simple Half-Heusler Topological Insulators.

Abstract: We predict the existence of triple point fermions in the band structure of several half-Heusler topological insulators by ab initio calculations and the Kane model We find that many half-Heusler compounds exhibit multiple triple points along four independent C_{3} axes, through which the doubly degenerate conduction bands and the nondegenerate valence band cross each other linearly nearby the Fermi energy When projected from the bulk to the (111) surface, most of these triple points are located far away from the surface Γ[over ¯] point, as distinct from previously reported triple point fermion candidates These isolated triple points give rise to Fermi arcs on the surface, that can be readily detected by photoemission spectroscopy or scanning tunneling spectroscopy