Document DOI: 10.1209/epl/i2002-00357-4
Europhys. Lett., 60 (2) , pp. 302-308 (2002)
Quantum tunneling in molecular ferric wheels
O. WaldmannPhysikalisches Institut III, Universität Erlangen-Nürnberg D-91058 Erlangen, Germany
(Received 7 January 2002; accepted in final form 5 August 2002)
Abstract
An effective spin Hamiltonian is presented which describes the
low-lying energy spectrum of antiferromagnetic molecular rings with
high accuracy. It will be shown that for the particular case of the
ferric wheels, quantum coherent phenomena are best discussed in terms
of resonant quantum tunneling of the spin vector between different
rotational modes. These quantum processes are associated to
anticrossings of higher-lying spin multiplets with
.
75.10.Jm - Quantized spin models.
75.50.Xx - Molecular magnets.
73.40.Gk - Tunneling.
© EDP Sciences 2002