Eur. Phys. J. B 43, 125-129 (2005)
https://doi.org/10.1140/epjb/e2005-00035-5

Decoherence and entanglement in coherent quantum tunneling of magnetization with dissipation

¹ Institute of Theoretical Physics and Department of Physics, Shanxi University, Taiyuan, 030006 Shanxi, P.R. China
² Department of Physics, Yanbei Normal Institute, Datong, 037000 Shanxi, P.R. China

Corresponding author: ^a nieyh@sxu.edu.cn

Received: 28 April 2004
Revised: 30 August 2004
Published online: 11 February 2005

Abstract

We study the coherent quantum tunneling of magnetization, for example, in a biaxial molecular magnet with dissipation of the environment which results in the suppression of the tunneling and therefore the decoherence of superposition of macroscopic quantum states in terms of the general spin-boson model. The degree of entanglement between the magnet and the environment is evaluated explicitly with the help of reduced density matrix. We show an interesting relation that the degree of entanglement approaches maximum value when the coherent tunneling is suppressed completely.