Chiral magnetic order at surfaces driven by inversion asymmetry
Top Cited Papers
- 1 May 2007
- journal article
- Published by Springer Science and Business Media LLC in Nature
- Vol. 447 (7141), 190-193
- https://doi.org/10.1038/nature05802
Abstract
Chirality is a fascinating phenomenon that can manifest itself in subtle ways, for example in biochemistry (in the observed single-handedness of biomolecules) and in particle physics (in the charge-parity violation of electroweak interactions). In condensed matter, magnetic materials can also display single-handed, or homochiral, spin structures. This may be caused by the Dzyaloshinskii-Moriya interaction, which arises from spin-orbit scattering of electrons in an inversion-asymmetric crystal field. This effect is typically irrelevant in bulk metals as their crystals are inversion symmetric. However, low-dimensional systems lack structural inversion symmetry, so that homochiral spin structures may occur. Here we report the observation of magnetic order of a specific chirality in a single atomic layer of manganese on a tungsten (110) substrate. Spin-polarized scanning tunnelling microscopy reveals that adjacent spins are not perfectly antiferromagnetic but slightly canted, resulting in a spin spiral structure with a period of about 12 nm. We show by quantitative theory that this chiral order is caused by the Dzyaloshinskii-Moriya interaction and leads to a left-rotating spin cycloid. Our findings confirm the significance of this interaction for magnets in reduced dimensions. Chirality in nanoscale magnets may play a crucial role in spintronic devices, where the spin rather than the charge of an electron is used for data transmission and manipulation. For instance, a spin-polarized current flowing through chiral magnetic structures will exert a spin-torque on the magnetic structure, causing a variety of excitations or manipulations of the magnetization and giving rise to microwave emission, magnetization switching, or magnetic motorsKeywords
This publication has 23 references indexed in Scilit:
- Spontaneous skyrmion ground states in magnetic metalsNature, 2006
- Real-Space Observation of Helical Spin OrderScience, 2006
- Time-Domain Measurements of Nanomagnet Dynamics Driven by Spin-Transfer TorquesScience, 2005
- Microwave oscillations of a nanomagnet driven by a spin-polarized currentNature, 2003
- Antimatter mattersNature, 2003
- Single-handed cooperationNature, 2001
- Emission of spin waves by a magnetic multilayer traversed by a currentPhysical Review B, 1996
- Current-driven excitation of magnetic multilayersJournal of Magnetism and Magnetic Materials, 1996
- Anisotropic Superexchange Interaction and Weak FerromagnetismPhysical Review B, 1960
- Zur Theorie des FerromagnetismusThe European Physical Journal A, 1928