外磁场中单畴反铁磁颗粒的宏观量子效应  

MACROSCOPIC QUANTUM EFFECT IN SINGLE DOMAIN ANTIFERROMAGNETIC PARTICLES IN AN EXTERNAL MAGNETIC FIELD 

作　　者：聂一行[1] 石云龙[2] 张云波[1] 梁九卿[1] 蒲富恪[3] 

机构地区：[1]山西大学物理系 [2]雁北师范学院物理系,大同037000 [3]中国科学院物理研究所

出　　处：《物理学报》2000年第8期1580-1585,共6页Acta Physica Sinica

基　　金：国家自然科学基金!(批准号:19775 0 33);山西省自然科学基金!(批准号:971008和981002)资助的课题

摘　　要：用瞬子方法研究了外加磁场对单畴双轴反铁磁颗粒宏观量子效应的影响 .当外磁场沿易磁化方向时 ,简并基态中的一个能量抬高 ,变为亚稳态 ,其隧穿衰变率随外磁场增大 ;当外磁场沿中间磁化方向时 ,能级的隧穿劈裂随外磁场的变化而振荡 .The effect of the external magnetic field on macroscopic quantum tunneling in biaxial single domain antiferromagnetic particles is studied with the help of the instanton method. It is shown that the decay rate increases with increasing external magnetic field applied along the easy axis of the magnetization, and that the tunneling splitting oscilates with respect to the external magnetic field in the direction of the medium axis. Our results may be helpful for experimental observation of the macroscopic quantum coherence and the tunneling decay in single domain antiferromagnetic particles.

关 键 词：量子隧穿 外磁场 单畴反铁磁颗粒 宏观量子效应 

分 类 号：O413[理学—理论物理]