Speaker
Miklos Lajko
(EPFL)
Description
We apply field theory methods to $\mbox{SU}(3)$ symmetric Heisenberg chains in the fully symmetric representation, with p boxes in the Young tableau, mapping them into a $\mbox{SU}(3)/(\mbox{U}(1)\times\mbox{U}(1))$ non-linear $\sigma$-model with a non-trivial topological term and a topological angle $\theta =2\pi p/3$. Based on this mapping we argue that $\mbox{SU}(3)$ spin chains are gapped for $p=3m$, while gapless for $p=3m\pm 1$ (for integer $m$). This is confirmed by Monte Carlo calculations on the $\sigma$-model. We further discuss the phase diagram and the renormalization flow of the $\sigma$-model, and its implications on spin chains.
Author
Miklos Lajko
(EPFL)
Co-authors
Mr
Kyle Wamer
(The University of British Columbia)
Prof.
Frédéric Mila
(EPFL)
Prof.
Ian Affleck
(The University of British Columbia)
