Dresden 2014 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 22: Low-Dimensional Systems: Charge Order
TT 22.2: Vortrag
Montag, 31. März 2014, 15:15–15:30, BEY 81
Electronic band structure of 1T-TaS2 and new implications for the Mott-phase — •Tobias Ritschel1,5, Jan Trinckauf1, Gaston Garbarino2, Alexei Bosak2, Martin von Zimmermann3, Klaus Koepernik1, Helmuth Berger4, Bernd Büchner1,5, and Jochen Geck1 — 1IFW, Dresden — 2ESRF, Grenoble — 3HASYLAB, Hamburg — 4Ecole polytechnique Federale de Lausanne — 5TU Dresden
The layered compound 1T-TaS2 exhibits a multitude of distinct charge density wave (CDW) phases as a function of temperature and pressure. A unique feature of 1T-TaS2 among the CDW systems is the occurrence of a commensurate (C)-CDW phase which is commonly described as a Mott-phase due to electron-electron interactions and which is extremely sensitive upon applying external pressure. We studied the electronic band structure of the C-CDW phase in terms of density functional theory (DFT) as a function of the amplitude of the lattice modulation. Surprisingly we found that the experimental electronic band structure of the so-called Mott-phase, can already be very well described by conventional DFT calculations in the local density approximation (LDA). Moreover slight changes of the amplitude of the lattice modulation have dramatic effects on the calculated band structure, which agrees very well with the strong pressure dependence of the C-CDW phase. We will discuss our results with respect to Mott-physics associated with the C-CDW phase and its pronounced sensitivity to pressure.