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PGI-1 Talk: Dr. Farideh Hajiheidari

Chiral Magnetic Interactions in Graphene Nanoribbons on Topological Insulator Substrates

18 Dec 2017 11:30
PGI Lecture Hall

RWTH University Aachen


It is known that the interplay between strong spin-orbit coupling and broken inversion symmetry can lead to chiral configurations in low-dimensional magnetic systems deposited on heavy-element surfaces. This phenomenon is due to the Dzyaloshinskii-Moriya interaction, which favours non-collinear magnetic structures. Here we show by ab initio simulations that this interaction leads to a twisting of the two antiferromagnetically-coupled edge states of a zigzag graphene nanoribbon deposited on the topological insulator Sb2Te3. To our knowledge, this is the first report of a chiral magnetic structure formed by these one-dimensional states. The resulting net magnetization of the nanoribbons shifts the Dirac point of the surface state of the topological insulator and can even induce a gap depending on its direction. These findings could lead to applications of graphene nanoribbons as spin filters in graphene-based spintronics devices.


Prof. Dr. Stefan Blügel
Phone: +49 2461 61-4249
Fax: +49 2461 61-2850
email: s.bluegel@fz-juelich.de