To determine the motion of a charged particle in a magnetic field produced by a current flowing along a long column conductor,the equation of the motion was established on the basis of Lorentz force. Qualitative analy...To determine the motion of a charged particle in a magnetic field produced by a current flowing along a long column conductor,the equation of the motion was established on the basis of Lorentz force. Qualitative analysis and quantitative solutions demonstrated that the motion contains nonlinear oscillation. The oscillation can be treated as the perturbation of the helical motion,which the particle undergoes in a special condition. The general motion is superposition of two helixes,one as an axis spiraled by another. It is proven that the oscillation is stable.展开更多
We report a detailed theoretical study of current oscillation and de-voltage-controlled chaotic dynamics in doped GaAs/AlAs resonant tunneling superlattices under crossed electric and magnetic fields. When the superla...We report a detailed theoretical study of current oscillation and de-voltage-controlled chaotic dynamics in doped GaAs/AlAs resonant tunneling superlattices under crossed electric and magnetic fields. When the superlattice is biased at the negative differential velocity region, current self-oscillation is observed with proper doping concentration. The current oscillation mode and oscillation frequency can be affected by the dc voltage bias, doping density, and magnetic field. When an ac electric field with fixed amplitude and frequency is also applied to the system, different nonlinear properties show up in the external circuit with the change of dc voltage bias. We carefully study these nonlinear properties with different chaos-detecting methods.展开更多
基金the key scientific research project of Sichuan Education Department(No.06A108).
文摘To determine the motion of a charged particle in a magnetic field produced by a current flowing along a long column conductor,the equation of the motion was established on the basis of Lorentz force. Qualitative analysis and quantitative solutions demonstrated that the motion contains nonlinear oscillation. The oscillation can be treated as the perturbation of the helical motion,which the particle undergoes in a special condition. The general motion is superposition of two helixes,one as an axis spiraled by another. It is proven that the oscillation is stable.
基金The project supported by the National Fund for Distinguished Young Scholars of China under Grant No. 60425415, the Major Project of National Natural Science Foundation of China under Grant No. 10390162, and the Shanghai Municipal Commission of Science and Technology under Grant Nos. 03JC14082 and 05XD14020
文摘We report a detailed theoretical study of current oscillation and de-voltage-controlled chaotic dynamics in doped GaAs/AlAs resonant tunneling superlattices under crossed electric and magnetic fields. When the superlattice is biased at the negative differential velocity region, current self-oscillation is observed with proper doping concentration. The current oscillation mode and oscillation frequency can be affected by the dc voltage bias, doping density, and magnetic field. When an ac electric field with fixed amplitude and frequency is also applied to the system, different nonlinear properties show up in the external circuit with the change of dc voltage bias. We carefully study these nonlinear properties with different chaos-detecting methods.
