Dynamical Response of Liquid 3He Films Adsorbed on Solid Substrates
Within the general framework of linear response theory, we investigate the excitation spectrum of 3He films adsorbed on substrates. Starting from the quasiparticle spectrum and the effective interaction derived in a finite range density functional scheme, we analyze the properties of the particle-ho...
Guardado en:
| Autores principales: | , |
|---|---|
| Publicado: |
2000
|
| Materias: | |
| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00222291_v120_n1-2_p1_Calbi http://hdl.handle.net/20.500.12110/paper_00222291_v120_n1-2_p1_Calbi |
| Aporte de: |
| Sumario: | Within the general framework of linear response theory, we investigate the excitation spectrum of 3He films adsorbed on substrates. Starting from the quasiparticle spectrum and the effective interaction derived in a finite range density functional scheme, we analyze the properties of the particle-hole (ph) excitations as well as the collective modes in the Random Phase Approximation. On the one hand, the most important features of the ph spectrum, originated in the band structure of the single particle spectrum together with the fermionic character of the quasiparticles, are clearly exhibited when the free response to a probe parallel or transverse to the film is considered. On the other hand, for any film, the collective spectrum presents various branches which, in many situations, can be associated with predominantly intraband longitudinal transitions or with almost pure interband transitions. Analyzing the RPA response of a monolayer on substrates of very different adsorbing power (cesium and graphite) we can interpret the nature of the existing collective excitations and determine the influence of the geometrical features of the film on the effective quasiparticle interaction responsible of these oscillations. |
|---|