L55.00011. Path integral for spin-1 chain in the entangled basis
Presented by: Jung Hoon Han
We develop path-integral formulation of spin-1 Haldane chain in the entangled, matrix product state (MPS) basis. Whereas the conventional path integral approach is founded on spin-based coherent states as the basis, we here adopt a new basis consisting of bond-based coherent states. The Affleck-Kennedy-Lieb-Tasaki (AKLT)-type ground state is obtained as the saddle point solution of the newly developed action. Small fluctuations around the saddle point are developed in terms of conventional gradient expansion. Ways to compute various correlation functions based on the effective action will be discussed. While certain crude approximations have to be made to proceed with the calculation, it appears that features of spin gap in the spin-1 chain seems nicely captured at the mean-field level by the path integral written in the entangled basis. This work was done in collaboration with Jin-Tae Kim, Rajarshi Pal, and Jin-Hong Park at SKKU.
- Jung Hoon Han