The quantum interference effects induced by the topological phase are studied analytically in biaxial antiferromagnets with an external magnetic field at an arbitrarily angle. This study provides a nontrivial generalization of the Kramers degeneracy for equivalent double-well system to coherently spin tunneling at ground states as well as low-lying excited states for antiferromagnetic system with asymmetric twin barriers. The spin-phase interference effects are found to depend on the orientation of the magnetic field distinctly.
@article{arxiv.cond-mat/0011487,
title = {Phase interference in antiferromagnetic quantum tunneling with an arbitrarily directed magnetic field},
author = {Rong Lu and Hui Pan and Jia-Lin Zhu and Bing-Lin Gu},
journal= {arXiv preprint arXiv:cond-mat/0011487},
year = {2007}
}