48 research outputs found
Photoelectron diffraction: from phenomenological demonstration to practical tool
The potential of photoelectron diffraction—exploiting the coherent interference of directly-emitted and elastically scattered components of the photoelectron wavefield emitted from a core level of a surface atom to obtain structural information—was first appreciated in the 1970s. The first demonstrations of the effect were published towards the end of that decade, but the method has now entered the mainstream armoury of surface structure determination. This short review has two objectives: First, to outline the way that the idea emerged and the way this evolved in my own collaboration with Neville Smith and his colleagues at Bell Labs in the early years: Second, to provide some insight into the current state-of-the art in application of (scanned-energy mode) photoelectron diffraction to address two key issue in quantitative surface structure determination, namely, complexity and precision. In this regard a particularly powerful aspect of photoelectron diffraction is its elemental and chemical-state specificity
Mechanically induced current and quantum evaporation from Luttinger liquids
We investigate transport through a tunnelling junction between an
uncorrelated metallic lead and a Luttinger liquid when the latter is subjected
to a time dependent perturbation. The tunnelling current as well as the
electron energy distribution function are found to be strongly affected by the
perturbation due to generation of harmonics in the density oscillations. Using
a semiconducting lead instead of a metallic one results in electrons being
injected into the lead even without applied voltage. Some applications to
carbon nanotubes are discussed.Comment: 7 pages, 2 figures (eps files
Plasmonic excitations in noble metals: The case of Ag
The delicate interplay between plasmonic excitations and interband
transitions in noble metals is described by means of {\it ab initio}
calculations and a simple model in which the conduction electron plasmon is
coupled to the continuum of electron-hole pairs. Band structure effects,
specially the energy at which the excitation of the -like bands takes place,
determine the existence of a subthreshold plasmonic mode, which manifests
itself in Ag as a sharp resonance at 3.8 eV. However, such a resonance is not
observed in the other noble metals. Here, this different behavior is also
analyzed and an explanation is provided.Comment: 9 pages, 8 figure