Regensburg 2000 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

TT: Tiefe Temperaturen

TT 21: Korrelierte Elektronen II

TT 21.7: Vortrag

Donnerstag, 30. März 2000, 16:15–16:30, H18

Spectral properties of incommensurate charge-density wave systems — •G. Seibold¹, F. Becca², F. Bucci³, C. Castellani³, C. Di Castro³, and M. Grilli³ — ¹Lehrstuhl Theoretische Physik, BTU Cottbus, 03013 Cottbus, Germany — ²Istituto Nazionale Di Fisica Della Materia and International School for Advanced Studies, Via Beirut 4, 34013 Trieste, Italy — ³Istituto Nazionale di Fisica della Materia e Dipartimento di Fisica, Università di Roma “La Sapienza”, Piazzale A. Moro 2, 00185 Roma, Italy

The concept of frustrated phase separation is applied to investigate its consequences for the electronic structure of the high T_c cuprates. The resulting incommensurate charge density wave (CDW) scattering is most effective in creating local gaps in k-space when the scattering vector connects states with equal energy. Starting from an open Fermi surface we find that the resulting CDW is oriented along the (1,0)- and (or) (0,1)-direction which allows for a purely one-dimensional or a two-dimensional “eggbox type” charge modulation. In both cases the van Hove singularities are substantially enhanced, and the spectral weight of Fermi surface states near the M-points, tends to be suppressed. Remarkably, a leading edge gap arises near these points, which, in the eggbox case, leaves finite arcs of the Fermi surface gapless. We discuss our results with repect to possible consequences for photoemission experiments.