Suppression of Magnetization Tunneling in Rare-Earth Atoms on Surfaces of Various Symmetry †
1
Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
2
Department of Physics and Astronomy, University of Canterbury, Christchurch 8041, New Zealand
*
Author to whom correspondence should be addressed.
†
Presented at Symmetry 2017—The First International Conference on Symmetry, Barcelona, Spain, 16–18 October 2017.
Proceedings 2018, 2(1), 5; https://doi.org/10.3390/proceedings2010005
Published: 9 January 2018
(This article belongs to the Proceedings of The First International Conference on Symmetry)
In the classical world, it is easy to store a bit of information. One needs a bistable system with a high enough barrier between the two ground states. Such a system is exemplified by a magnetic cluster with uniaxial anisotropy, so that the direction of the magnetic moment encodes the information.
On the nanoscale, a high barrier is not enough. Fourteen years ago, P. Gambardella et al. found that single Co atoms on Pt (111) have high enough anisotropy energy to have stable magnetization at low temperatures [1]. Later investigations [2,3] showed, however, that the magnetization of those atoms and similar systems switches on nanosecond timescales. Interaction with the electron bath of the substrate allows “magnetization tunneling”, where the system switches between two ground states aided by elastic electron scattering.
The probability of such switching depends on the symmetry of the ground state wavefunctions, which in turn is determined by the symmetry of the adsorption site and the total angular momentum of the magnetic atom. An appropriate combination of these symmetries leads to a first-order suppression of the tunneling process, stabilizing the magnetic state.
We classify the possible symmetry combinations and analyse recent experimental reports of magnetically stable rare-earth atoms in light of this theory.
References
- Gambardella, P.; Rusponi, S.; Veronese, M.; Dhesi, S.S.; Grazioli, C.; Dallmeyer, A.; Cabria, I.; Zeller, R.; Dederichs, P.H.; Kern, K.; et al. Giant magnetic anisotropy of single cobalt atoms and nanoparticles. Science 2003, 300, 1130–1133. [Google Scholar] [CrossRef] [PubMed]
- Balashov, T.; Schuh, T.; Takács, A.F.; Ernst, A.; Ostanin, S.; Henk, J.; Mertig, I.; Bruno, P.; Miyamachi, T.; Suga, S.; et al. Magnetic Anisotropy and Magnetization Dynamics of Individual Atoms and Clusters of Fe and Co on Pt(111). Phys. Rev. Lett. 2009, 102, 257203. [Google Scholar] [CrossRef] [PubMed]
- Loth, S.; Etzkorn, M.; Lutz, C.P.; Eigler, D.M.; Heinrich, A.J. Measurement of fast electron spin relaxation times with atomic resolution. Science 2010, 329, 1628–1630. [Google Scholar] [CrossRef] [PubMed]
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
MDPI and ACS Style
Balashov, T.; Karlewski, C.; Märkl, T.; Schön, G.; Wulfhekel, W. Suppression of Magnetization Tunneling in Rare-Earth Atoms on Surfaces of Various Symmetry. Proceedings 2018, 2, 5. https://doi.org/10.3390/proceedings2010005
AMA Style
Balashov T, Karlewski C, Märkl T, Schön G, Wulfhekel W. Suppression of Magnetization Tunneling in Rare-Earth Atoms on Surfaces of Various Symmetry. Proceedings. 2018; 2(1):5. https://doi.org/10.3390/proceedings2010005
Chicago/Turabian StyleBalashov, Timofey, Cristian Karlewski, Tobias Märkl, Gerd Schön, and Wulf Wulfhekel. 2018. "Suppression of Magnetization Tunneling in Rare-Earth Atoms on Surfaces of Various Symmetry" Proceedings 2, no. 1: 5. https://doi.org/10.3390/proceedings2010005
