https://doi.org/10.1007/s100510170048
The role of layer-thickness deviation in dispersion and structure of plasmons in finite superlattices
Department of Physics and Astronomy, Western
Washington University, Bellingham, 98225, Washington, USA
Corresponding author: a bljohnso@physics.wwu.edu
Received:
16
April
2001
Revised:
6
July
2001
Published online: 15 October 2001
We study the effects of layer thickness variations on the collective plasmon excitation modes of finite superlattices. Unlike other symmetry lowering mechanisms, thickness variation does not strongly localize the surface modes. We find that the reason for this insensitivity lies in the fact that the collective modes of a given finite structure must evolve continuously from the single-finite-superlattice at zero thickness deviation into modes of a pair of uncoupled finite structures at large thickness variation. We also show that this behavior is analogous to the evolution of molecular orbitals from atomic orbitals as the internuclear separation is reduced, in contrast to the analogy of the superlattice modes as a stack of coupled quantum wells. This emphasizes the difference between the electromagnetic symmetry of the finite superlattice and the structural symmetry.
PACS: 73.21.-b – Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems / 73.21.Cd – Superlattices
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001