双频激励下超晶格系统的混沌行为
Chaotic Behaviour of Superlattice with Dual Frequency Excitation
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摘要: 假设超晶格“折沟道”对粒子的作用等效为形状相似的周期调制; 引入正弦平方势, 在小振幅近似下, 把粒子运动方程化为具有双频激励的Duffing方程。 用Melnikov方法分析了系统的混沌行为。 结果表明, 当外场为双频激励时, 系统将存在不同的次谐和超次谐分叉序列。 由于系统的混沌行为与系统参数有关, 于是, 只需控制材料组分、 或掺杂浓度, 就可望达到避免或控制混沌的目的, 为半导体超晶格的制备及其光磁电效应提供了理论分析。
Abstract: It is assumed that a periodic modulation is equivalent to deflected channel of the superlattice. In the small amplitude approximation the particle motion equation is simplified to the Duffing equation with a hardspring properties by using sinesquared potential. The chaotic behaviour is analysed by Melnikov method.It shows that the subharmonic bifurcation and the supersubharmonic bifurcation are presented in the system, the chaos can be controlled by controlling the parameters of the system.The result provided a theoretical analysis for the study of the photomagnetoelectric effects of superlattice.