, is a number characterizing many-body states that possess topological order.
Given a topologically ordered state, the topological entropy can be extracted from the asymptotic behavior of the Von Neumann entropy measuring the quantum entanglement between a spatial block and the rest of the system.
The entanglement entropy of a simply connected region of boundary length L, within an infinite two-dimensional topologically ordered state, has the following form for large L: where
The topological entanglement entropy is equal to the logarithm of the total quantum dimension of the quasiparticle excitations of the state.
You can help Wikipedia by expanding it.This article about statistical mechanics is a stub.