CaIrO3: a spin-orbit Mott insulator beyond the j(eff) ground state.
In CaIrO3, electronic correlation, spin-orbit coupling, and tetragonal crystal field splitting are predicted to be of comparable strength. However, the nature of its ground state is still an object of debate, with contradictory experimental and theoretical results. We probe the ground state of CaIrO3 and assess the effective tetragonal crystal field splitting and spin-orbit coupling at play in this system by means of resonant inelastic x-ray scattering. We conclude that insulating CaIrO3 is not a j(eff) = 1/2 iridate and discuss the consequences of our finding to the interpretation of previous experiments. In particular, we clarify how the Mott insulating state in iridates can be readily extended beyond the j(eff) = 1/2 ground state.
European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France.
M Moretti
MM
Sala
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
K
K
Ohgushi
European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France.
A
A
Al-Zein
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Y
Y
Hirata
European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France and Dipartimento di Fisica, Università di Trento, via Sommarive 14, 38123 Povo (TN), Italy.
G
G
Monaco
European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France.
M
M
Krisch