CPHT Condensed Matter seminar

Tuesday, September 12 at 14:00

at CPHT, Conference room Louis Michel

Naoya Iwahara (Chiba University, Japan)

Dynamic Jahn-Teller effect in cubic spin-orbit Mott insulators

Abstract: The synergistic interplay of different interactions in materials leads to the emergence of novel quantum phenomena. Spin-orbit and vibronic couplings usually counteract each other; however, in cubic 4d/5d double perovskites they can coexist and give rise to spin-orbit-lattice entanglement (dynamic Jahn-Teller effect) on the metal sites. The correlation of these entangled states induced by intersite interactions has not been assessed so far. In the seminar, I will first show that the dynamic Jahn-Teller effect develops in iridium compounds based on the analysis of the resonant inelastic x-ray scattering spectra [1]. Then, I will talk about the ordering of the entangled states in a series of cubic 5d1 double perovskites [2]. The magnetically ordered states in these systems coexist with a vibronic order characterized by the ordering of vibronic quadrupole moments on sites. This treatment allows for the rationalization of a number of unexplained features of experimentally investigated phases.

[1] N. Iwahara and W. Furukawa, Phys. Rev. B 108, 075136 (2023).
[2] N. Iwahara and L. F. Chibotaru, Phys. Rev. B 107, L220404 (2023).