https://doi.org/10.1140/epjd/e20020055
Landau fragmentation and deformation effects in dipole response of sodium clusters
1
Bogoliubov Laboratory of Theoretical Physics,
Joint Institute for Nuclear Research, Dubna 141980, Moscow region,
Russia
2
Technische Universität Dresden,
Institut für Analysis, 01062 Dresden, Germany
3
Institut für Theoretische Physik,
Universität Erlangen, 91058 Erlangen, Germany
Corresponding author: a nesteren@theorie2.physik.uni-erlangen.de
Received:
26
October
2001
Revised:
11
December
2001
Published online: 15 April 2002
Recent experimental data on the dipole plasmon in axial sodium
clusters Na
with 
are analyzed within
a self-consistent separable random-phase approximation (SRPA) based on
the deformed Konh-Sham functional. Good agreement with the data
is achieved. The calculations show that, while in light clusters
plasmon properties (gross structure and width) are determined
mainly by deformation splitting, in medium clusters with N>50
the Landau fragmentation becomes decisive. Moreover, in medium clusters
shape isomers come to play with contributions to the plasmon
comparable with the ground state one. As a result,
commonly used methods of the experimental analysis of cluster
deformation become useless and correct treatment
of cluster shape requires microscopic calculations.
PACS: 36.40.-c – Atomic and molecular clusters / 36.40.Gk – Plasma and collective effects in clusters / 36.40.Vz – Optical properties of clusters
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002
