Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2008-05-07
Phys. Rev. B 78, 094427 (2008)
Physics
Condensed Matter
Strongly Correlated Electrons
39 pages, 24 figures
Scientific paper
10.1103/PhysRevB.78.094427
We consider the spin--orbital model for a magnetic system with singly occupied but triply degenerate $t_{2g}$ orbitals coupled into a planar, triangular lattice, as would be exemplified by NaTiO$_2$. We investigate the ground states of the model for interactions which interpolate between the limits of pure superexchange and purely direct exchange interactions. By considering ordered and dimerized states at the mean--field level, and by interpreting the results from exact diagonalization calculations on selected finite systems, we demonstrate that orbital interactions are always frustrated, and that orbital correlations are dictated by the spin state, manifesting an intrinsic entanglement of these degrees of freedom. In the absence of Hund coupling, the ground state changes from a highly resonating, dimer--based, symmetry--restored spin and orbital liquid phase, to one based on completely static, spin--singlet valence bonds. The generic properties of frustration and entanglement survive even when spins and orbitals are nominally decoupled in the ferromagnetic phases stabilized by a strong Hund coupling. By considering the same model on other lattices, we discuss the extent to which frustration is attributable separately to geometry and to interaction effects.
Normand Bruce
Oles' Andrzej M.
No associations
LandOfFree
Frustration and entanglement in the $t_{2g}$ spin--orbital model on a triangular lattice: valence--bond and generalized liquid states does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Frustration and entanglement in the $t_{2g}$ spin--orbital model on a triangular lattice: valence--bond and generalized liquid states, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frustration and entanglement in the $t_{2g}$ spin--orbital model on a triangular lattice: valence--bond and generalized liquid states will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-491764