Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 57: Poster IIa

HL 57.8: Poster

Dienstag, 8. März 2005, 16:30–19:00, Poster TU E

Correlation effects in dense mass-asymmetric electron-hole plasmas — •Michael Bonitz¹, Vladimir Filinov², Vladimir Fortov², Pavel Levashov², and Holger Fehske³ — ¹Institute for Theoretical Physics and Astrophysics, Christian-Albrechts-University Kiel, Leibnizstrasse 15, 24098 Kiel — ²Institute for High Energy Density, Russian Academy of Sciences, Moscow, Russia — ³Institute of Physics, Ernst-Moritz-Arndt-University Greifswald

Insulating excitonic phases in strongly correlated semiconductors, insulator-metal transition and the possibility of exciton Bose condensation are attracting increasing interest, e.g. [1].

A theoretical approach which is particularly well suited to describe these phenomena is the path integral quantum Monte Carlo (PIMC) method. We present simulation results for the excitonic phase diagram of TmSe_0.45Te_0.55 which was measured in Ref. [1]. In particular, we calculate the fraction of the electron-hole and hole-hole bound states, pair correlation functions, snapshots of the particle positions, internal energy and equation of state of a mass-asymmetric electron-hole plasma. Data for the isotherms T=30-300 K are presented. Density-temperature regions have been found for existence of excitons, bi-excitons and many-particle clusters. The transition to a metallic state is detected [2].

[1] P. Wachter, B. Bucher, and J. Malar, Phys. Rev. B 69, 094502 (2004); [2] V. Filinov, H. Fehske, and M. Bonitz, New J. Phys. (2005)