Spin transport

Semiconductor spintronics offers the possibility to develop hybrid devices that can perform the processing, communication, and storage of information within one chip. The investigations on spin transport phenomena in ferromagnet/semiconductor hybrid structures aim at the understanding of the underlying physical mechanisms as well as the evaluation and/or identification of their relevance for spintronic device concepts.


In order to study the generation and transport of non-equilibrium spin polarizations in non-magnetic materials, lateral spin valve structures are utilized. In the case of semiconductor transport channels with ferromagnetic contacts, even features of the electronic band structure in the contact material can be extracted via the bias voltage dependence of the spin generation process. For example, using spin valves with GaAs transport channels, the theoretically predicted half-metallic character of the Heusler alloy Co2FeSi was confirmed, an important material property which is otherwise very difficult to access.


One current focus is the integration of two-dimensional materials into hybrid spintronic transport structures, including also vertical spin valve devices. In this context, the layered materials Fe3GeTe2 and α-FeGe2 are promising candidates for ferromagnetic materials. In particular, van der Waals heterostructures consisting of a few atomic layers of one of the ferromagnetic materials with graphene or h-BN as spacers will be explored. Such layered structures may allow for the tailoring of magnetic and electronic properties via interfacial engineering.



1 Author D. Czubak , S. Gaucher , L. Oppermann , J. Herfort , K. Zollner , J. Fabian , H. T. Grahn , M. Ramsteiner

Electronic and magnetic properties of alpha-FeGe2 films embedded in vertical spin valve devices

Source Phys. Rev. Mater. , 4 , 104415 ( 2020 )
DOI : 10.1103/PhysRevMaterials.4.104415 | Download arXiv: 2010.04453 | 3196 Cite : Bibtex RIS
D. Czubak, S. Gaucher, L. Oppermann, J. Herfort, K. Zollner, J. Fabian, H. T. Grahn, and M. Ramsteiner


Prof. Dr. Holger T. Grahn

Head of Department 

+49 30 20377-318