The atomic and electronic structure of an As vacancy on the GaAs(110) surface is examined using ab initio pseudopotentials. The relaxed atomic structure reveals an inward movement of the neighboring surface Ga atoms which is in disagreement with recent interpretations of the scanning tunneling microscopy (STM) images for this system. However, a careful analysis of the wave-function character of...

Variation of the local electronic structure at rutile TiO2(110) surfaces was studied by scanning tunneling spectroscopy ~STS!. Structural surface features such as step edges, (132) reconstructed strands, and their terminations were correlated to changes in tunneling spectra. In particular, band-gap states, associated with a reduced surface, showed characteristic variations. In addition, electro...

In scanning tunneling experiments on semiconductor surfaces, the energy scale within the tunneling junction is usually unknown due to tip-induced band bending. Here, we experimentally recover the zero point of the energy scale by combining scanning tunneling microscopy with Kelvin probe force spectroscopy. With this technique, we revisit shallow acceptors buried in GaAs. Enhanced acceptor-relat...

Localized spectroscopy with simultaneous topographic, elemental and magnetic information is presented. A synchrotron X-ray scanning tunneling microscope has been employed for the local study of the X-ray magnetic circular dichroism at the Fe L2,3-edges of a thin iron film grown on Cu(111). Polarization-dependent X-ray absorption spectra have been obtained through a tunneling smart tip that serv...

Acenes are intriguing molecules with unique electronic properties. The difficulties in their preparation owing to low stability under ambient conditions are apparent because successful syntheses of long unsubstituted acenes are still scarce, in spite of the great attention they have attracted. Only unsubstituted acenes up to heptacene have been isolated in bulk, with nonacene being the largest ...

We report on the study of atomically sharp superconducting tips for scanning tunneling microscopy and spectroscopy. The results clearly show vacuum tunneling of superconducting quasiparticles from atomically sharp tips. Observed deviations of the energy gap of the superconducting tip from its bulk value are attributed to the proximity effect. We show that a combination of a superconducting tip ...

The effect of the carboxylic acid substituent position of phenyleneethynylene systems on the 2D self-organization is revealed by scanning tunneling microscopy.

Bowl-in-bowl stacking of buckybowls on a copper surface is observed via scanning tunneling microscopy (STM) at low temperatures and characterized by density functional theory (DFT) calculations.

Supramolecular patterns formed by adsorption from a liquid of nucleobase-terminated molecular rods on a graphite surface were investigated by scanning tunneling microscopy.