门电压诱导的单分子磁体磁滞效应

摘要

基于率方程研究了温差驱动的单分子磁体中,门电压诱导的磁滞效应.当门电压从某一负值缓慢地增加到某一正值再从该正值返回到负值时,分子磁体磁化强度对门电压的响应曲线不重合,而是一条闭合磁滞回线.这种磁滞效应是分子磁体的宏观量子效应,只出现在低温下,可以从分子态占据概率对门电压的依赖来解释.此外,还讨论了温度、铁磁电极极化率以及交换作用对磁滞回线所围面积的影响.%The gate voltage induced hysteresis in single molecule magnet with temperature difference is investigated by using the rate equation.When the gate voltage slowly increases from negative value to positive value and reaches a certain value,and then returns its initial value,the response curve of molecule magnet magnetization to gate voltage is not coincide and forms a hysteresis loop.The hysteresis loop in single molecule magnet is a macroscopic quantum effect and appears only at low temperature and can be explained by dependence of the occupation probability of molecule state on the gate voltage.Moreover,the effects of the temperature,polarization of the ferromagnetic electrode and spin exchange interaction on the area of hysteresis loops is discussed.