Motivated by studies of coexisting electron correlation and spin-orbit coupling effect in Na2IrO3 and a recent experiment of its 4d analogue Li2RhO3, we performed first-principles calculations of the rhodium oxide compound. The experimentally observed ground state of Li2RhO3 can be recovered only if both spin-orbit coupling and on-site Coulomb interaction are taken into consideration. Within the proper U range for 4d-orbitals (2⩽U⩽4 eV), the ground state of Li2RhO3 could be either zigzag-AFM or stripy-AFM, both yielding energy gap close to experimental observation. Furthermore, the total energy differences between the competing magnetic phases are ⩽3 meV/Rh within 2⩽U⩽4 eV, manifesting strong magnetic frustration in the compound. Finally, the phase energy of Li2RhO3 cannot be fitted with the two-dimensional Heisenberg-Kitaev model involving only the nearest neighbor interactions, and we propose that inter-layer interactions may be responsible for the discrepancy.
@article{arxiv.1303.4675,
title = {Electronic structure of relativistic Mott insulator Li$_2$RhO$_3$},
author = {Chao Cao and Yongkang Luo and Zhuan Xu and Jianhui Dai},
journal= {arXiv preprint arXiv:1303.4675},
year = {2013}
}