ELFT HÍRADÓ

[bordacs.sandor AT wigner.bme.hu]

Kedves Kollégák!

Szeretném figyelmükbe ajánlani a BME Fizika Tanszékének Nanofizika 
szemináriumának következő előadását.

Előadó: Kézsmárki István – MTA-BME Magneto-optikai Spektroszkópia 
Lendület Kutatócsoport

Cím: Observation of Neel-type Skyrmion Lattice in a Polar Magnetic 
Semiconductor

Időpont: 2015. március 31. (kedd) 10:30
Helyszín: BME F. épület I. lh. 1. em. Schay terem

Asztrakt: Following the early prediction of the skyrmion lattice (SkL) - 
a periodic
array of spin vortices - it has been observed recently in various 
magnetic
crystals mostly with chiral structure. Although non-chiral but polar
crystals with C_nv symmetry were identified as ideal SkL hosts in
pioneering theoretical studies, this archetype of SkL has remained
experimentally unexplored. Here, we report the discovery of a SkL in the
polar magnetic semiconductor GaV4S8 with rhombohedral (C_3v) symmetry 
and
easy axis anisotropy. The SkL exists over an unusually broad temperature
range compared with other bulk crystals and the orientation of the
vortices is not controlled by the external magnetic field but instead
confined to the magnetic easy axis. Supporting theory attributes these
unique features to a new Neel-type of SkL describable as a superposition
of spin cycloids in contrast to the Bloch-type SkL in chiral magnets
described in terms of spin helices.

[1] http://arxiv.org/abs/1502.08049

Minden érdeklődőt szívesen látunk!

--
Dr. Sandor Bordacs
assistant prof.
MTA-BME Lendulet Magneto-optical Spectroscopy Research Group
Department of Physics, Budapest University of Technology and Economics
http://magnetooptics.phy.bme.hu
Tel: 36-1-4633056
Fax: 36-1-4634180