Abstract
Building on the generalization of the exactly dimerized Majumdar-Ghosh ground state to arbitrary spin for the Heisenberg chain with a three-site term , we use density-matrix renormalization group simulations and exact diagonalizations to determine the nature of the dimerization transition for , , and 2. The resulting central charge and critical exponent are in good agreement with the Wess-Zumino-Witten values and . Since the three-site term that induces dimerization appears naturally if exchange interactions are calculated beyond second order, these results suggest that Wess-Zumino-Witten models might finally be realized in actual spin chains.
- Received 24 January 2013
DOI:https://doi.org/10.1103/PhysRevB.87.140404
©2013 American Physical Society