Dynamic Structure Factor of Dusty and Low‐Dimensional Plasmas

Abstract

Experiences investigating the dynamic structure factor of dense plasmas are applied to complex plasmas, in particular to dusty plasmas and dimensionally reduced plasmas. Using generalized linear response theory, the dynamical structure factor is obtained from a density response function expressed in terms of equilibrium correlation function. Corrections beyond the RPA approximation are taken into account by evaluating localfield corrections within the recurrance method. Results for the dynamic structure factor of a Yukawa plasma is compared with molecular dynamics calculations. . Concepts from standard dense ionic plasmas are extended to new systems. The aim is to probe the limits of applicability and to get new insight into the relevant microscopic processes in strongly coupled plasmas. It is also expected that such systems may exhibit new properties which are of interest with respect to technical applications.An important example for plasmas with reduced dimensionality is the electron-hole-exciton system produced in semiconductor heterostructures. In contrast to standard ionic plasmas, in addition to the Coulomb interaction the excitation and recombination of electron-hole pairs is of importance. They are presently of increasing interest, since the manufacturing of such nanostructured materials is experimentally feasible and of technological importance. The theoretical investigations of such systems is one aspect in the search for materials with certain desired properties and new applications. Layered, two-dimensional structures can be found not only in semiconductor heterostructures, but also in different physical systems such as ion traps or dusty plasmas where chemical reactions are also of interest.Dusty plasmas are multicomponent plasmas consisting of charged micron-sized particles, electrons, ions, and a neutral background gas. In such a system, the micron-sized particles also referred to as dust grains can attain high charges of several 10 3 e. Ikezi has pointed out, that the interaction between these highly charged dusty particles may lead to strong structural ordering [3]. In particular, liquid phases and plasma crystals have been predicted and also observed experimentally [4].Special experimental effort is necessary to stabilize dusty plasmas. At present, dusty plasmas have been studied in all dimensions, as 1D chains [5], 2D layers [6], and 3D systems. An elegant method to avoid the influence of gravitation which disturbs the formation of a stationary plasma state are microgravity experiments performed in space stations or in ballistic vehicles.Under certain conditions, the inter-dust potential in dusty plasmas can be approximated by a one-component system of negatively charged dust grains immersed in a uniform background of opposite charge and interacting via a Yukawa potential [7] V (r) = Q

Dielectric Function of a Quantum-Confined Thin Film with a Modified Pöschel–Teller Potential

“…It is known that, in the two-dimensional geometry, the screening results in an essentially different spatial dependence of the dielectric function, as compared with that obtained in the three-dimensional case. If the interaction between particles is considered, the screening of the electric field created by charges in those structures has to be taken into account correctly [10][11][12].…”

“…is the modified Pöschel-Teller potential confining the electron motion. The energy spectrum and the oneelectron normalized wave functions for the charge carriers were obtained in works [10][11][12][13]:…”