Fermi arcs and pseudogap emerging from dimensional crossover at the Fermi surface in La2−xSrxCuO4
1 R. Bošković Institute - Bijenička cesta 54, HR-10000 Zagreb, Croatia
2 Department of Physics, Faculty of Science, University of Zagreb - Bijenička cesta 32, HR-10000 Zagreb, Croatia
Received: 2 August 2015
Accepted: 2 November 2015
The doping mechanism and realistic Fermi surface (FS) evolution of La2−xSrxCuO4 (LSCO) are modelled within an extensive ab initio framework including advanced band-unfolding techniques. We show that ordinary Kohn-Sham DFT+U can reproduce the observed metal-insulator transition, when not restricted to the paramagnetic solution space. Arcs are self-doped by orbital charge transfer within the Cu-O planes, while the introduced Sr charge is strongly localized. Arc protection and the inadequacy of the rigid-band picture are consequences of a rapid change in orbital symmetry at the Fermi energy: the material undergoes a dimensional crossover along the Fermi surface, between the nodal (2D) and antinodal (3D) regions. In LSCO, this crossover accounts for FS arcs, the antinodal pseudogap, and insulating behavior in c-axis conductivity, all ubiquitous phenomena in high-Tc cuprates. Ligand Coulomb integrals involving out-of-plane sites are principally responsible for the most striking effects observed by ARPES in LSCO.
PACS: 74.72.Gh – Hole-doped / 74.20.Pq – Electronic structure calculations / 74.25.Jb – Electronic structure (photoemission, etc.)
© EPLA, 2015