Abstract
In this Letter, some relations between the topological parameter d and concurrences of the projective entangled states have been presented. It is shown that for the case with d = n, all the projective entangled states of two n-dimensional quantum systems are the maximally entangled states (i.e. C = 1). And for another case with d not equal n, C both approach 0 when d -> +infinity for n = 2 and 3. Then we study the thermal entanglement and the entanglement sudden death (ESD) for a kind of Yang-Baxter Hamiltonian. It is found that the parameter d influences not only the critical temperature T-c but also the maximum entanglement value that the system can arrive at. And we also find that the parameter d has a great influence on the ESD. (C) 2012 Elsevier B.V. All rights reserved.