Entanglement temperature in molecular magnets composed of -spin dimers

¹  Instituto de Física de São Carlos, Universidade de São Paulo - P.O. Box 369, 13560-970, São Carlos, SP, Brazil
²  Centro Brasileiro de Pesquisas Físicas - Rua Dr. Xavier Sigaud 150, 22290-180, Rio de Janeiro, Brazil
³  Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo Waterloo, Ontario, N2L 3G1, Canada
⁴  CICECO, Universidade de Aveiro - 3810-193, Aveiro, Portugal, EU
⁵  Departamento de Química, Universidade de Aveiro - 3810-193 Aveiro, Portugal, EU
⁶  NSSD, ORNL - Oak Ridge, TN 37831-6475, USA

Corresponding author: diogo.osp@ursa.ifsc.usp.br

Received: 4 May 2009
Accepted: 17 August 2009

Abstract

In the present work, we investigate the quantum thermal entanglement in molecular magnets composed of dimers of spin S, using an Entanglement Witness built from measurements of magnetic susceptibility. An entanglement temperature, T_e, is then obtained for some values of spin S. From this, it is shown that T_e is proportional to the intradimer exchange interaction J and that entanglement appears only for antiferromagnetic coupling. The results are compared to experiments carried on three isostructural materials: (M=Mn, Fe or Cu).