Multiferroic magnetic spirals induced by random magnetic exchanges
| Autor: | Scaramucci, Andrea, Shinaoka, Hiroshi, Mostovoy, Maxim V., Müller, Markus, Mudry, Christopher, Troyer, Matthias, Spaldin, Nicola A. |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Phys. Rev. X 8, 011005 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevX.8.011005 |
| Popis: | Multiferroism can originate from the breaking of inversion symmetry caused by magnetic-spiral order. The usual mechanism for stabilizing a magnetic spiral is competition between magnetic exchange interactions differing by their range and sign, such as nearest-neighbor and next-nearest- neighbor interactions. Since the latter are usually weak the onset temperatures for multiferroism via this mechanism are typically low. By considering a realistic model for YBaCuFeO$_5$ we propose an alternative mechanism for magnetic-spiral order, and hence for multiferroism, that occurs at much higher temperatures. We show using Monte-Carlo simulations and electronic structure calculations based on density functional theory that the Heisenberg model on a geometrically non-frustrated lattice with only nearest-neighbor interactions can have a spiral phase up to high temperature when frustrating bonds are introduced randomly along a single crystallographic direction as caused, e.g., by a particular type of chemical disorder. This long-range correlated pattern of frustration avoids ferroelectrically inactive spin glass order. Finally, we provide an intuitive explanation for this mechanism and discuss its generalization to other materials. Comment: 7 pages, 4 figures and supplemental material (8 pages and 6 figures) |
| Databáze: | arXiv |
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