Thursday's CM Colloquium

[Condensed_Matter_Group]

JOINT ICTP/SISSA

COLLOQUIUM    ON CONDENSED MATTER PHYSICS



Wednesday, 14 December -  4:00 p.m.



Luigi Stasi Seminar Room,  ICTP Leonardo Building (1st floor)


Angela Burlamaqui KLAUTAU, (Universidade Federal do Para’, Belem)


"Nanostructures on metallic surfaces: Novel magnetic properties"




Abstract

The magnetic properties of nanostructures supported on metallic surfaces
are of great interest, both because of the possibilities of atomic
engineering of future spintronic devices, as well as due to the fact that
such systems challenge our understanding of magnetism in general. Here,
our research on the magnetic properties of nano-sized objects adsorbed on
different substrates will be reviewed. Such theoretical investigations
were performed using DFT (Density Functional Theory) based method, which
is appropriate to treat complex magnetic structures [1]. From nanowires to
corrals, we have explored the possibility of the occurrence of novel
magnetic behaviors. A systematic study of the occurrence of noncollinear
magnetism is presented, by changing the geometry of the supported
nanostructures, where intriguing noncollinear magnetic ordering were
obtained for Mn nanostructures adsorbed on Pt(111) [2], Fe(001) and W(001)
surfaces. In particular, for Mn corrals on Pt(111) surfaces we identified
a nano¬object presenting very complex stable magnetic configurations,
which can be described by topological structures, as Skyrmions, in analogy
to Z2 vortex¬like structures [2]. Also, for Mn nanostructures on Fe(001)
the effect of spin-orbit coupling lead to the possibility of half
skyrmion. Concerning metallic nanowires of Mn on W(001), we show the
possibility of realizing complex noncollinear magnetic structures such as
helical spin spiral.
[1] A. Bergman, L. Nordström, A. B. Klautau, S. Frota¬Pessôa and O.
Eriksson, Phys. Rev. B 73, 174434 (2006); Phys. Rev. B 75, 224425 (2007).
[2] M. S. Ribeiro, G. B. Corrêa Jr., A. Bergman, L. Nordström, O.
Eriksson, and A. B. Klautau, Phys. Rev. B 83, 014406 (2011).