Regensburg 2000 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 22: Postersitzung III: Supraleitende Anwendungen (1-4) Massive HTSL, Bandleiter, Filme (5-26), Transport in HTSL (27-30), Elektronenstruktur in Supraleitern (31-43), Borkarbide (44-50), Quantenphasen- und Metall-Isolator-Überg
änge (51-69)
TT 22.59: Poster
Donnerstag, 30. März 2000, 14:00–17:30, A
Doping dependence of the Néel temperature in Mott-Hubbard antiferromagnets — •Carsten Timm and K.H. Bennemann — Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin
The doping dependence of the Néel temperature TN in doped Mott-Hubbard antiferromagnets is investigated theoretically. We start from recent results of electronic theory for hole-doped high-Tc cuprates, which show that holes can dress with antiferromagnetic vortices. These results can be understood as a natural consequence of frustration of the exchange interaction due to holes at the oxygen sites. We also discuss the relevance of magnetic anisotropies, in particular of the Dzyaloshinskii-Moriya anisotropy. We describe the magnetic phase transition within a generalized Berezinskii-Kosterlitz-Thouless renormalization-group theory and obtain good agreement of TN with experiments on high-Tc cuprates. The antiferromagnetic order at T=0 vanishes at a critical doping of xc∼ 0.02, which is independent of all energy scales of the system.