Macroscopic quantum coherence of the Neel vector in antiferromagnetic system without Kramers' degeneracy R. Lü, J.-L. Zhu, X. Chen and L. Chang Eur. Phys. J. B, 3 1 (1998) 35-40 Published online: 15 May 1998 DOI: 10.1007/s100510050281