Hamburg 2001 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 6: Postersitzung I: Josephsonkontakte und SQUIDs, Supraleitung: Theorie, Korrelierte Elektronen, Niederdimensionale Systeme, Magnetotransport, Quantenhalleffekt, Kohlenstoff-Nanoröhrchen, Quantenflüssigkeiten

TT 6.23: Poster

Montag, 26. März 2001, 14:30–17:00, Rang S\ 3

Phenomenological Approach to Photoemission Spectra of Strongly Correlated Electron Systems — •Krzysztof Byczuk, Ralf Bulla, and Dieter Vollhardt — Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute for Physics, University of Augsburg, 86135 Augsburg, Germany

A simple analytical formula for the self-energy of strongly correlated electrons is proposed. This self-energy, when inserted in the Hilbert integral for the density of states, reproduces both coherent (quasiparticle) and incoherent (Hubbard subbands) parts of the spectrum. Free parameters in the formula are determined by fitting the calculated density of states to experimental photoemission data. Such an explicit fitting is presented for La_1−xSr_xTiO₃ system with x=0.04, 0.06, 0.08, 0.18, 0.28, 0.36, and 0.65 [1,2]. In general, our method combined with fitting to direct and inverse photoemission data provides information on the effective mass, the Hubbard interaction, and the spectral weight distribution in different parts of the density of state.

[1] A. Fujimori et al., Phys. Rev. B 46, 9841 (1992).

[2] T. Yoshida et al., cond-mat/9911446.