We have investigated the ground-state and the thermal entanglement properties of a two-dimensional frustrated spin 1/2 cluster by calculating the pairwise concurrence and negativity. It is found that an increase in temperature can lead to an enhancement of pairwise entanglement for a certain range of the frustration parameter. We have, also, found that negativity is equal to the half of the concurrence for the model considered here. (c) 2006 Elsevier B.V. All rights reserved.
机构:
Inst Fed Educ Ciencia & Tecnol Rio de Janeiro IFRJ, Rua Dr Jose Augusto Pereira Santos S-N,CIEP 436 Ne, BR-24425004 Sao Goncalo, RJ, BrazilUniv Fed Amazonas, Dept Fis, 3000 Japiim, BR-69077000 Manaus, AM, Brazil