The McMillan-Rowell tunneling inversion program, which extracts the electron-phonon spectral function aF(V) and the Coulomb pseudopotential m* from experimental tunneling data, is generalized to include the lowest-order vertex correction. We neglect the momentum dependence of the electron-phonon matrix elements, which is formally equivalent to using a local approximation. The perturbation theor...

We use electron tunneling to measure electronic energy levels in individual nm-scale Al particles. For sufficiently large particles (*5 nm in radius), the eigenstate energies reveal the existence of a superconducting excitation gap V which is driven continuously to zero by an applied magnetic field. The presence of V increases the voltage threshold for tunneling in a particle with an even numbe...

Spatial resolution at the atomic scale has been achieved in the coupling of light to single molecules adsorbed on a surface. Electron transfer to a single molecule induced by green to near-infrared light in the junction of a scanning tunneling microscope (STM) exhibited spatially varying probability that is confined within the molecule. The mechanism involves photo-induced resonant tunneling in...

The influence of relative electron tunneling rates on electron transport in a double-barrier single-molecule junction is studied. The junction is defined by positioning a scanning tunneling microscope tip above a copper phthalocyanine molecule adsorbed on a thin oxide film grown on the NiAl(110) surface. By tuning the tip-molecule separation, the ratio of tunneling rates through the two barrier...

The exact semiclassical wave function for a tunneling electron, coupled to the degrees of freedom of the host medium, is constructed. In our derivation the tunneling path is divided into an infinite set of infinitezimal segments and the decaying solutions of the stationary Shrödinger equations are matched for each neighboring segment from the beginning to the end of the tunneling path. This sol...

We have performed a density functional study of the electronic structure, images and vibrationally inelastic tunneling in the scanning tunneling microscope and vibrational damping by excitation of electron-hole pairs of CO chemisorbed on the (111) and (100) faces of Cu. We find that the 2 pi* molecular orbital of CO turns into a broad resonance with parameters that differ significantly from tho...

Motivated by a recent tunneling experiment in a double quantum-well system, which reports an anomalously enhanced electronic scattering rate in a clean two-dimensional electron gas, we calculate the inelastic quasiparticle lifetime due to electron-electron interaction in a single loop dynamically screened Coulomb interaction within the random-phase-approximation. We obtain excellent quantitativ...

We consider a four-terminal setup of a two-dimensional topological insulator (quantum spin Hall insulator) with local tunneling between the upper and lower edges. The edge modes are modeled as helical Luttinger liquids and the electron-electron interactions are taken into account exactly. Using perturbation theory in the tunneling, we derive the cumulant generating function for the interedge cu...

In this paper we review studies on spin-dependent transport in systems contain-ing ferromagnetic nanoparticles. In a tunnel junction with a nanometer-scale-island, the charging effect leads to an electric current blockade phenomenon inwhich a single electron charge plays a significant role in electron transport, re-sulting in single-electron tunneling (SET) properties such a...