有机磁体中极化子漂移的动力学模拟

Dynamical Simulation of Polaron Drift in Organic Magnetic Polymers

采用一维紧束缚模型,研究了一维有机磁性聚合物中极化子在外加电场下漂移的动力学行为.计算结果表明:侧基和主链电子的自旋耦合使得侧基悬挂格点上电子的在位能升高(或降低),作为一个势垒(势井)阻碍极化子的运动.当驱动电场大于某临界值时,极化子会突破势垒(势井)的束缚,在磁性聚合物分子内自由漂移.磁性聚合物分子中的自旋反转因素可以通过调节极化子自旋降低临界电场.

The dynamical properties of polaron drift with external driven electric field in organic magnetic polymers are investigated base on a one-dimensional tight-binding model. The results indicate that the spin correlation of electrons between the main chain and the side radicals raises （or drops） the electron energy on the sites which side radical connects. This produces a potential barrier （or potential well） on the site to stop the polaron from drifting along the chain unless the driven electric field is larger than the critical value. On the other hand, the spin flip mechanisms in organic magnetic polymers can adjust the strength of the critical electric field by influencing the spin of polaron and other electrons on the main chain.