Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 31: Surface and Interface Magnetism I (jointly with MA)

O 31.10: Vortrag

Dienstag, 12. März 2013, 12:45–13:00, H33

Atomically assembled antiferromagnets — •Sebastian Loth — Max Planck Research Group-Dynamics of Nanoelectronic Systems, Center for Free-Electron Laser Science, Hamburg — Max Planck Institute for Solid State Research, Stuttgart

When atoms are placed into regular arrays their magnetic moments can interact and form long-range ordered magnetic states. In particular antiferromagnetic spin coupling creates a large variety of possible collective states. We use low-temperature scanning tunneling microscopy to construct few-atom antiferromagnets. Their shapes can be defined precisely by atom manipulation. In this way uncompensated magnetic moments at the nanoparticle's edge can be avoided. We use such spin-compensated atomic arrays to study the intrinsic dynamics of nanoscale antiferromagnets [1]. For two-dimensional arrays of growing size we can trace the transition from the quantum mechanical singlet ground state to doubly degenerate Neel-type states. Arrays with ten or more atoms can be stable in each state for several hours but current-induced switching between the metastable spin states proceeds at nanosecond speed. These properties enable a model demonstration of dense magnetic data storage using antiferromagnets memory elements.

[1] S. Loth, S. Baumann, C. P. Lutz, D. M. Eigler, A. J. Heinrich, Science 335, 196 (2012).