Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 17: Low-Dimensional Systems: Oxide Hetero-Interfaces

TT 17.5: Vortrag

Montag, 7. März 2016, 16:15–16:30, H22

Magnetism, spin texture and in-gap states: Atomic specialization at the surface of oxygen-deficient SrTiO₃ — •Harald O. Jeschke¹, Michaela Altmeyer¹, Marcelo Rozenberg², Marc Gabay², and Roser Valenti¹ — ¹Institut für Theoretische Physik, Goethe-Universität Frankfurt, Max-von-Laue-Straße 1, 60438 Frankfurt am Main, Germany — ²Laboratoire de Physique des Solides, Bat 510, Université Paris-Sud, 91405 Orsay, France

We investigate the electronic structure and spin texture at the (001) surface of SrTiO₃ in the presence of oxygen vacancies by means of ab initio density functional theory (DFT) calculations of slabs. Relativistic non-magnetic DFT calculations exhibit Rashba-like spin winding with a characteristic energy scale ∼ 10 meV. However, when surface magnetism on the Ti ions is included, bands become spin-split with an energy difference ∼ 100 meV at the Γ point. This energy scale is comparable to the observations in SARPES experiments performed on the two-dimensional electronic states confined near the (001) surface of SrTiO₃. We find the spin polarized state to be the ground state of the system, and while magnetism tends to suppress the effects of the relativistic Rashba interaction, signatures of it are still clearly visible in terms of complex spin textures.