Hidden topological order in integer quantum spin chains

Abstract
Using an idea of Rommelse and den Nijs, we have investigated a direct analogy between the topological order in integer quantum antiferromagnets and the topological order in the fractional quantum Hall effect (FQHE). Numerical results are presented for the S = 1 generalized Heisenberg chain. The analogy between the Laughlin gap in the FQHE and the Haldane gap in integer spin chains is discussed.