Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2011-01-27
Phys. Rev. B 83, 245130 (2011)
Physics
Condensed Matter
Strongly Correlated Electrons
18 pages, 16 figures
Scientific paper
10.1103/PhysRevB.83.245130
We study the dynamics and thermodynamics of one-dimensional spin-orbital models relevant for transition metal oxides. We show that collective spin, orbital, and combined spin-orbital excitations with infinite lifetime can exist, if the ground state of both sectors is ferromagnetic. Our main focus is the case of effectively ferromagnetic (antiferromagnetic) exchange for the spin (orbital) sector, respectively, and we investigate the renormalization of spin excitations via spin-orbital fluctuations using a boson-fermion representation. We contrast a mean-field decoupling approach with results obtained by treating the spin-orbital coupling perturbatively. Within the latter self-consistent approach we find a significant increase of the linewidth and additional structures in the dynamical spin structure factor as well as Kohn anomalies in the spin-wave dispersion caused by the scattering of spin excitations from orbital fluctuations. Finally, we analyze the specific heat c(T) by comparing a numerical solution of the model obtained by the density-matrix renormalization group with perturbative results. At low temperatures T we find numerically c(T) T pointing to a low-energy effective theory with dynamical critical exponent z=1.
Herzog Adrian
Horsch Peter
Oles' Andrzej M.
Sirker Jesko
No associations
LandOfFree
Magnetic excitations in one-dimensional spin-orbital models 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 Magnetic excitations in one-dimensional spin-orbital models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic excitations in one-dimensional spin-orbital models will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-545540