Spin-orbit coupling in the Mott insulator Ca(2)RuO(4).
O 1s x-ray absorption study of the Mott insulator Ca(2)RuO(4) shows that the orbital population of the 4d t(2g) band dramatically changes with temperature. In addition, spin-resolved circularly polarized photoemission study of Ca(2)RuO(4) shows that a substantial orbital angular momentum is induced in the Ru 4d t(2g) band. Based on the experimental results and model Hartree-Fock calculations, we argue that the cooperation between the strong spin-orbit coupling in the Ru 4d t(2g) band and the small distortion of the RuO(6) octahedra causes the interesting changeover of the spin and orbital anisotropy as a function of temperature.
Mizokawa
T
T
Department of Complexity Science and Engineering, University of Tokyo, Tokyo 113-0033, Japan.
Tjeng
L H
LH
Sawatzky
G A
GA
Ghiringhelli
G
G
Tjernberg
O
O
Brookes
N B
NB
Fukazawa
H
H
Nakatsuji
S
S
Maeno
Y
Y