Dynamical response function of a compressed lithium monolayer

Abstract

Since recent both theoretical and experimental results have proved that the simple behaviour light alkaline metals present at equilibrium breaks when high pressures are applied, they have become an important object of study in Condensed Matter Physics. On the other hand, development of new techniques in the atomic manipulation allows the growth of atomic monolayers (ML's), therefore rising the interest to analyze low dimensional systems under different conditions. In particular, new ab initio calculations performed for a lithium ML show that its electronic properties experience important modifications under pressure, which could lead to significant modifications in its dynamical response function. In this article we perform ab initio calculations of the dynamical response function of a lithium ML analyzing its evolution with increasing applied pressure. We show that besides the well known intraband and interband plasmons, rising electronic density induces characteristic features of acoustic plasmons related to the presence of two types of carriers at the Fermi level.

The influence of electron confinement, quantum size effects, and film morphology on the dispersion and the damping of plasmonic modes in Ag and Au thin films

“…Shockley surface states existing at the (1 1 1) surfaces of noble metals [56,149,[366][367][368][369][370][371][372][373][374] support this collective excitation, which owes its existence to the spatial coexistence of a 2DEG with a 3D electron gas. In Ag the excitation is ascribed to the screening of the Shockley surface states electrons by bulk electrons [367,375], while recent results have indicated that in both Au [150] and Cu [376] the opposite phenomenon occurs: slow bulk electrons are screened by the faster surface state electrons.…”

Low-energy plasmons in quantum-well and surface states of metallic thin films

“…[59][60][61][62][63][64][65][66][67] One can see in Fig. 6 that surface excitation spectra evaluated in the jellium model are rather featureless in this low-energy domain compared to Fig.…”