Quantum-size effects in the loss function of Pb(111) thin films: An ab initio study

Abstract

A theoretical study of the surface energy-loss function of freestanding Pb(111) thin films is presented, starting from the single monolayer case. The calculations are carried applying the linear response theory, with inclusion of the electron band structure by means of a first-principles pseudopotential approach using a supercell scheme. Quantum-size effects on the plasmon modes of the thinnest films are found in qualitative agreement with previous work based on the jellium model. For thicker films, results show a dispersionless mode at all thicknesses, in agreeement with electron energy-loss measurements. For sizeable values of the momentum, the raising of the surface plasmon with increasing thickness is retrieved.

Ultrathin Bismuth Film on High-Temperature Cuprate Superconductor Bi2Sr2CaCu2O8+δ as a Candidate of a Topological Superconductor

“…As shown in Figure d, the calculated band structure near E F looks very different between 2- and 3-BL Bi(110). This is due to the quantum-size effect, which strongly modifies the band structure near E F , particularly in the case of thin semimetal films, as revealed by the slab calculations. − …”

Formation of Surface and Quantum-Well States in Ultra Thin Pt Films on the Au(111) Surface

“…Frequently, the quantization of electronic states in thin films in the direction perpendicular to surface can be understood rather well in the framework of a semiclassical description based on a Fabry–Perot-type approach [ 15 ]. Even though the potential corrugation at the interatomic scale caused by the atoms can have some effect [ 68 , 69 , 70 ], this basic picture for description of quantization of the s - p electronic states still can be valid. However, many important materials have an electronic structure being far different from a quasi-free-electron-like picture.…”

Surface plasmons on Pd(110): An ab initio calculation

“…We understand such behavior as a consequence of the effect of interband transitions involving the d valence states, which are not included in the reference result within the Drude model. It is actually known that even in a relatively simple metal such as lead, the band structure effects are sufficiently large to disturb the surface excitation spectra [78].…”