Electronically driven spin-reorientation transition of the correlated polar metal Ca$_3$Ru$_2$O$_7$
| Autor: | Marković, I., Watson, M. D., Clark, O. J., Mazzola, F., Morales, E. Abarca, Hooley, C. A., Rosner, H., Polley, C. M., Balasubramanian, T., Mukherjee, S., Kikugawa, N., Sokolov, D. A., Mackenzie, A. P., King, P. D. C. |
|---|---|
| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1073/pnas.2003671117 |
| Popis: | Polar distortions in solids give rise to the well-known functionality of switchable macroscopic polarisation in ferroelectrics and, when combined with strong spin-orbit coupling, can mediate giant spin splittings of electronic states. While typically found in insulators, ferroelectric-like distortions can remain robust against increasing itineracy, giving rise to so-called "polar metals". Here, we investigate the temperature-dependent electronic structure of Ca$_3$Ru$_2$O$_7$, a correlated oxide metal in which octahedral tilts and rotations combine to mediate pronounced polar distortions. Our angle-resolved photoemission measurements reveal the destruction of a large hole-like Fermi surface upon cooling through a coupled structural and spin-reorientation transition at 48 K, accompanied by a sudden onset of quasiparticle coherence. We demonstrate how these result from band hybridisation mediated by a hidden Rashba-type spin-orbit coupling. This is enabled by the bulk structural distortions and unlocked when the spin reorients perpendicular to the local symmetry-breaking potential at the Ru sites. We argue that the electronic energy gain associated with the band hybridisation is actually the key driver for the phase transition, reflecting a delicate interplay between spin-orbit coupling and strong electronic correlations, and revealing a new route to control magnetic ordering in solids. Comment: Contains 6+5 pages, including supplementary information |
| Databáze: | arXiv |
| Externí odkaz: |
|