Macroscopic Quantum Phase Interference in Antiferromagnetic Particles
  The tunnel splitting in biaxial antiferromagnetic particles is studied with a magnetic field applied along the hard anisotropy axis. We observe the oscillation of tunnel splitting as a function of the magnetic field due to the quantum phase interference of two tunneling paths of opposite windings. The oscillation is similar to the recent experimental result with Fe}$_8$\textrm{\ molecular clusters.} 
Yi-Hang Nie, Yan-Hong Jin, J.-Q.Liang, H.J.W.M\"uller-Kirsten,   D.K.Park, F.-C.Pu