Abstract
We present a low-energy effective field theory to describe the bilinear-biquadratic spin chain. We start with and construct the effective theory by using six Majorana fermions. After determining various correlation functions, we characterize the phases and establish the relation between the effective theories for SO(6) and SO(5). Together with the known results for and 4, a reduction mechanism is proposed to understand the ground state for arbitrary . Also, we provide a generalization of the Lieb-Schultz-Mattis theorem for . The implications of our results for entanglement and correlation functions are discussed.
- Received 8 April 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.077204
© 2011 American Physical Society