- https://www.cells.es/en/media/events/alba-public-events/electronically-highly-cubic-conditions-for-ru-in-alpha-rucl3
- Electronically highly cubic conditions for Ru in alpha-RuCl3
- 2017-09-08T16:00:00+02:00
- 2017-09-08T17:00:00+02:00
- Dr. Stefan Agrestini from MPI CPfS Dresden.
- When
- Sep 08, 2017 from 04:00 PM to 05:00 PM (Europe/Madrid / UTC200)
- Where
- Marie Curie Briefing Room
- Contact Name
- Inma Hernández
- Contact Phone
- 935924389
- Attendees
- NOTE: If you are interested in attending, please contact Inma Hernández with your Identity Card number and name to obtain the ALBA access.
- Add event to calendar
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Abstract
Spin-orbit coupling active transition metal compounds, such as iridates and RuCl3, have received tremendous attention due to the high expectations of finding new exotic phenomena and the long-sought materialization of the Kitaev model. Prerequisite for these expectations is that the non-cubic crystal field splitting is small compared to the spin-orbit coupling (SOC) and, hence, does not perturb in a significant way the description of the electronic ground state in terms of the J_eff = 1/2 state. These “electronically cubic conditions” are much more stringent in RuCl3 than in iridates, since the SOC of Ru (~150 meV) is three times smaller than for Ir. In this context, contradictory reports are available in literature.
In this talk I present a study of the local Ru 4d electronic structure of RuCl3 by means of polarization dependent x-ray absorption spectroscopy at the Ru-L2,3 edges. The observed linear dichroism is vanishingly small indicating that electronically the Ru 4d local symmetry is highly cubic. Consistent with our magnetic circular dichroism measurements, the ratio of the orbital and spin moments is found to be 2.0, the value expected for a J_eff = 1/2 ground state. The data thus show that as far as the Ru 4d local properties are concerned, RuCl3 is an ideal candidate for the realization of the Kitaev physics.
