TY - INPR
A1 - Nie, Yi-Hang
A1 - Zhang, Y.-B.
A1 - Liang, J.-Q.
A1 - MÃ¼ller-Kirsten, H.J.W.
A1 - Pu, F.-C.
T1 - Macroscopic Quantum Coherence in Small Antiferromagnetic Particle and the Quantum Interference Effects
N2 - Starting from the Hamiltonian operator of the noncompensated two-sublattice model of a small antiferromagnetic particle, we derive the e effective Lagrangian of a biaxial antiferromagnetic particle in an external magnetic field with the help of spin-coherent-state path integrals. Two unequal level-shifts induced by tunneling through two types of barriers are obtained using the instanton method. The energy spectrum is found from Bloch theory regarding the periodic potential as a superlattice. The external magnetic field indeed removes Kramers' degeneracy, however a new quenching of the energy splitting depending on the applied magnetic field is observed for both integer and half-integer spins due to the quantum interference between transitions through two types of barriers.
KW - macroscopic quantum coherence
KW - instanton method
KW - level splitting
Y1 - 1999
UR - https://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/1158
UR - https://nbn-resolving.org/urn:nbn:de:hbz:386-kluedo-10960
ER -