Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 65: Poster Session Topological Topics

TT 65.10: Poster

Donnerstag, 19. März 2020, 15:00–19:00, P2/EG

Magnetoelectric screening at the interface of a topological insulator and a ferromagnetic insulator — •Marius Scholten1, Ilya Eremin2, Jeroen van den Brink1,3, and Flavio S. Nogueira11Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany — 2Institut für Theoretische Physik III, Ruhr-Universität Bochum, D-44780 Bochum, Germany — 3Institute for Theoretical Physics, TU Dresden, 01069 Dresden, Germany

It is well known that a ferromagnetic insulator (FMI) proximate to the surface of a topological insulator (TI) gaps the Dirac fermions when the out-of-plane component of the magnetization at the interface is non-vanishing. Consequently, a Chern-Simons (CS) term is generated by fluctuations of the Dirac fermions at the TI surface. This CS term consists of a magnetoelectric (ME) coupling and an additional Berry phase for the interface magnetization. For nonzero chemical potential, integrating out the Dirac fermions also generates a Dzyaloshinskii-Moriya interaction (DMI) which stabilizes skyrmions at the TI-FMI interface. In this work we discuss the consequences of the interplay between the CS and DMI terms in the effective action for the electrical screening. We discuss how the ME coupling to the magnetization modifies the dielectric function as a function of temperature and how this may lead to anti-screening effects at the interface. The dependence of the dielectric constant on temperature follows from the behavior of the interfacial magnetic susceptibility, which due to the DMI term also features a momentum space instability at the Curie temperature.

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2020 > Dresden