On the origin of the metal-insulator transition in Nd2Ir2O7 : a RIXS study
Vendredi 23 janvier 2015 11:30
- Duree : 1 heure
Lieu : Room 1-45, LOB Lab and Office Building, ESRF - 71 avenue des Martyrs - Grenoble
Orateur : Christian DONNERER (University College of London)
The nature of the metal-insulator transition observed in the pyrochlore iridates is intriguing : The interplay of the strong spin-orbit coupling, electronic correlations and geometric frustration has been predicted to give rise to exotic insulating ground states, such as topological Mott insulators and Weyl semimetals [1-3]. We performed a resonant inelastic x-ray scattering (RIXS) experiment on the pyrochlore iridate Nd2Ir2O7. Through crystal field excitations we inferred the electronic ground state. Crucially, the (effective) j=1/2 state, typically assumed to be realised in iridates, has to be modified due to trigonal distortions. Furthermore, we observed a low energy feature that we interpret as a magnetic excitation. This allows to identify the hierarchy of energy scales at play in Nd2Ir2O7 and address the mechanism of the metal-insulator transition from an experimental point of view.
[1] D. Pesin and L. Balents. Nature Physics 6.5 (2010) : 376-381.
[2] X. Wan et al. Physical Review B 83.20 (2011) : 205101.
[3] L. Savary, E.-G. Moon and L. Balents. Phys. Rev. X 4.4 (2014) : 041027.
Contact : marco.moretti@esrf.fr
Prévenir un ami par email
Télécharger dans mon agenda
RSS 2.0 : Tous les evenements