量子点磁化动力学行为的研究

利用Monte-Carlo方法研究磁性量子点阵列在不同交换耦合常数Jex、偶极相互作用常数D和磁各向异性常数K下的磁化曲线及自旋组态.模拟结果表明,对于不同的Jex和D,系统表现出不同的磁化行为和自旋组态;当Jex=0.0,D取小值时,量子点阵列的磁性基本保持了孤立原子团的磁特性,矫顽力随温度变化关系与单个的磁性原子团的相似,在低温区,矫顽力随温度的增加急剧减少;在中间温区,出现矫顽力极小;在更高温区,矫顽力随温度的增加而减少.

Study of Magnetic Dynamic Properties for Quantum Dots

Base on the Monte-Carlo simulation,the effect of exchange interaction constant Jex,dipolar interaction constant D and magnetic anisotropy constant K on magnetization curves,spin configuration of quantum dots are studied.It is found that the system displays different magnetization behavior and spin configuration for different Jex and D.When Jex=0.0 and the value of D is small,there exist almost same magnetic properties between quantum dots and single cluster.The relation between coercivity and temperature(Hc-T curve) of quantum dots is similar to that of single cluster.The coercivity decreases dramatically with increasing temperature in the low temperature region,the minimum of the coercivity appears in middle temperature region,and the coercivity drops again with increasing temperature in the high temperature region.