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[ISSP Colloquiums]
Topologically protected spin-textures in ultrathin metallic films
Title : Topologically protected spin-textures in ultrathin metallic films
Date :
Time :
2014/11/11(Tue)
4:00 PM -  
Place : Lecture Room (A632), 6th Floor, ISSP   
Lecturer : Prof. Dr. Stefan Blügel
Affiliation : Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich
Summary : In a recent work we could show the relevance of the Dzyaloshinskii-Moriya (DM) interaction in ultrathin films deposited on metal surfaces [1]. This opened a completely new vista in the field of research on magnetism of thin films. Appling first-principles calculations based on the density functional theory to ultrathin magnetic films, we explored the Dzyaloshinskii-Moriya interaction caused by spin-polarized electrons in the structure inversion asymmetric environment of 3d metal films on W substrates. We found that due to the large spin-orbit interaction of the W substrate the Dzyaloshinskii interaction exceeds a critical strength and competes with the exchange interaction and causes the formation of one-dimensional short-period cycloidal magnetic spirals of unique winding sense in the Mn film [1, 2]. The phenomenon is more general than expected and was also found for finite magnetic wires of Fe-double chains grown in troughs of the reconstructed Ir(100)5x1 substrates [3]. Also the effect of the Dzyaloshinskii-Moriya interaction on the domain-walls may be discussed [4]. Recently we could go one step further and theoretically design a magnetic film, a monolayer of Fe on Ir(111) that exhibits a lattice of non-trivial two-dimensional magnetic structures, a nano-Skyrmion lattice [5]. We explore the phase diagram of the magnetic system based on parameters obtained from first-principles and finite size effects e.g. finite Fe clusters on Ir(111).

[1] M. Bode, M. Heide, K. von Bergmann, S. Heinze, G. Bihlmayer, A. Kubetzka, O. Piet-zsch, S. Blügel, R. Wiesendanger, Nature 447, 190 (2007).
[2] P. Ferriani, K. von Bergmann, E.Y. Vedmedenko, S. Heinze, M. Bode, M. Heide, G. Bihl-mayer, A. Kubetzka, S. Blügel, R. Wiesendanger, Phys. Rev. Lett. 101, 027201 (2008).
[3] M. Menzel, Y. Mokrousov, R. Wieser, J. E. Bickel, E. Vedmedenko, S. Blügel, S. Heinze, K. von Bergmann, A. Kubetzka, and R. Wiesendanger, Phys. Rev. Lett. 108, 197204 (2012).
[4] M. Heide, G. Bihlmayer, and S. Blügel, Phys. Rev. B 78, 140403 (R) (2008); and Physica B 404, 2678 (2009).
[5] S. Heinze, K. von Bergmann, M. Menzel, J. Brede, A. Kubetzka, R. Wiesendanger, G. Bihlmayer, and S. Blügel, Nature Phys. 7, 713 (2011).
Contact : Organizer: Minoru YAMASHITA(ext.63350), Hiroshi NOGUCHI(ext.63265)