Regensburg 2019 – wissenschaftliches Programm
TT 3.5: Vortrag
Montag, 1. April 2019, 10:30–10:45, Theater
Topological insulator - ferrimagnet interface: Bi2Te3 on Fe3O4 — •Vanda M. Pereira1, Chi-Nan Wu1,2, Cariad Knight1,3, Simone G. Altendorf1, and Liu Hao Tjeng1 — 1Max Planck Institute for Chemical Physics of Solids, Dresden, Germany — 2Department of Physics, National Tsing Hua University, Hsinchu, Taiwan — 3University of British Columbia, Vancouver, Canada
Breaking the time reversal symmetry (TRS) of a topological insulator (TI) can lead to exotic phenomena such as the quantum anomalous Hall effect. In order to break the TRS, one can dope the system with transition metal elements. An alternative way to introduce magnetic order is to interface the TI with a magnetic layer, for instance a ferrimagnetic insulator (FI), making use of the proximity effect. This approach can be more advantageous, since it avoids the non-uniformity and disorder of the doping process.
Here we present the study on the growth of TI/FI heterostructures, namely Bi2Te3/Fe3O4, making use of our expertise in growing high quality thin films of these materials [1,2]. The preparation of the films by molecular beam epitaxy and their in-situ structural and spectroscopic characterization will be discussed. We were able to achieve a good quality interface, indicated by the minimal chemical reaction observed by X-ray photoelectron spectroscopy. Furthermore, angle-resolved photoemission spectroscopy indicates the presence of a sharp Dirac cone and the consequent preservation of the top topological surface states of the TI layer.
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