Hamburg 2001 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.31: Poster

Donnerstag, 29. März 2001, 15:45–18:15, Foyer S\ 3

Collective versus single-particle effects in the optical spectra of finite electronic quantum systems — •Mark Santer and Bernhard Mehlig — Theoretische Quantendynamik, Fakultät für Physik, Universität Freiburg, Hermann-Herder Str. 3, 79104 Freiburg i. Brsg.

We study optical spectra of finite electronic quantum systems at frequencies smaller than the plasma frequency using a quasi-classical approach, valid for systems of any shape and dynamics (diffusive or ballistic, regular or irregular motion). This approach includes collective effects and enables us to analyze how the nature of the (single-particle) electron dynamics influences the optical spectra in finite electronic quantum systems. We derive an analytical expression for the low-frequency absorption coefficient of electro-magnetic radiation in a finite quantum system with ballistic electron dynamics and specular reflection at the boundaries. By comparing with numerical computations using the random-phase approximation we show that our analytical approach provides a qualitative and quantitative understanding of optical spectra in finite electronic quantum systems. [cond-mat/0011315].