Surface-state linewidth from scanning tunnelling spectroscopy

摘要: The STM can be used to investigate lifetimes of hot holes in a surface state at low temperatures. We analysed dI/dV data from Ag(111) using detailed tunnelling calculations and simple model found an electron self-energy Σ=4.9±0.6 meV. corresponding lifetime τ= 67±8 fs is considerably higher than those determined by angle-resolved photoemission, although it remains below theoretical predictions. Spatially resolved spectra reveal that the decreases drastically proximity defects such as steps.