Collective excitations of strongly coupled bilayer charged Bose liquids in the third-frequency-moment sum rule
Date
2008Source Title
Physical Review B - Condensed Matter and Materials Physics
Print ISSN
1098-0121
Publisher
The American Physical Society
Volume
78
Issue
11
Pages
115324-1 - 115324-6
Language
English
Type
ArticleItem Usage Stats
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Abstract
We calculate the collective excitation modes of strongly coupled bilayer charged Bose systems. We employ the dielectric matrix formulation to study the correlation effects within the random-phase approximation (RPA), the self consistent field approximation Singwi, Tosi, Land, and Sjölander (STLS), and the quasilocalized charge approximation (QLCA), which satisfies the third-frequency-moment (〈ω3〉) sum rule. We find that the QLCA predicts a long-wavelength correlation-induced energy gap in the out-of-phase plasmon mode, similar to the situation in electronic bilayer systems. The energy gap and the plasmon density of states are studied as a function of interlayer separation and coupling parameter rs. The results should be helpful for experimental investigations.