Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2011-06-30
Physics
Condensed Matter
Strongly Correlated Electrons
6 pages
Scientific paper
Through exact diagonalization study of the spin - 1/2 Heisenberg model on Kagome lattice with ring-exchange coupling $J_{r}$, we find the pure Heisenberg model with $J_{r}=0$ stands as a quantum critical point, as evidenced by avoided level crossing and divergence of the second derivative of the ground state energy with respect to $J_{r}$ at $J_{r}=0$. The pure Heisenberg model should thus be gapless in the thermodynamic limit, contrary to common beliefs. At the same time, the ring exchange coupling is found to drive the system into a state with more short ranged spin correlation and with a local spin correlation pattern equivalent to that of the antiferromagnetic Heisenberg model on triangular lattice(the peak of spin structure factor moves to the momentum $\vec{q}=(\frac{4\pi}{3},0)$). The resemblance of state with the Marston-Zeng spin Pereils solid state(in terms of dimer-dimer correlation) is also much enhanced by the ring exchange coupling, although it is unclear if such correlation would solidify into static order in the thermodynamic limit.
No associations
LandOfFree
The spin - 1/2 Heisenberg model on Kagome lattice as a quantum critical system 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 The spin - 1/2 Heisenberg model on Kagome lattice as a quantum critical system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The spin - 1/2 Heisenberg model on Kagome lattice as a quantum critical system will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-34737