准二维4×4量子点磁化动力学特性的Monte Carlo模拟

Magnetic dynamic properties for quasi-two-dimensional 4×4 quantum dots: Monte Carlo simulation

摘要: 基于Monte Carlo模拟,研究了准二维4×4量子点阵列中交换相互作用常数J、偶极相互作用常数D、磁晶各向异性常数K对自旋组态和相关磁特性的影响。模拟结果表明,量子点阵列和单个量子点表现出完全不同的磁特性,即量子点阵列表现为顺磁性,而单个量子点则为铁磁性;分析不同外磁场下体系自旋组态的变化可以很好地解释模拟结果。

Abstract: In this paper,an in-plane quasi two-dimensional 4×4 quantum dot array（QDA） has been considered.Base on Monte Carlo simulation,the effect of exchange interaction constant J,dipolar interaction constant D,magnetic anisotropy constant K on spin configuration and magnetic properties of QDA have been studied.The simulated results indicate that the magnetization curves of QDA and single quantum dot（SQD） show very different behavior.QDA shows paramagnetic phase,but SQD in QDA shows ferromagnetic phase below Tc.The simulated results may be well explained by analyzing vary of spin configuration in difference magnetic field.