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In this Letter, a d’Alembert–Schrödinger hybrid method is proposed to analyze the transient interaction between the incident electromagnetic control pulse and the electron. This hybrid method is based on the d’Alembert equation, which describes the propagation of the electromagnetic field and the time-dependent Schrödinger equation, which describes the action of the electron. Moreover, the finite-difference time-domain method is used to solve those equations. In our simulation, using the presented hybrid equations and the control equation of the quantum state, a scheme is presented to design laser pulses to control discrete quantum states in a three-dimensional artificial atom model. Excitingly, the laser pulses have been successfully designed for the perfect four quantum states’ transition for the first time. With that, the spatiotemporal distribution for the probability density of an electron wave packet is showed in detail to describe the laser-induced transition process of quantum states.

The input current ripple problem of DC/DC converters receives more and more attention recently. To meet the increasingly demanding requirements, the fundamental components of the current ripple are researched and the corresponding current ripple reduction methods are proposed in this paper. On the one hand, due to the imbalance between the input and output power of the whole system when connected to the grid, the 100-Hz bus voltage ripple is induced. If the bus voltage ripple cannot be regulated effectively, the 100-Hz ripple will be reflected in the DC input side. On the other hand, with low pulse-width modulation (PWM) resolution, the quantized error of digital control is accumulated, which causes the quantized input current ripple. The 100-Hz ripple and the quantized ripple are the main input current ripple components. To solve the problems, a small-signal model of the DC/DC converter is built to calculate the input current ripple mathematically. Based on the theoretical analysis, the proportional-integral-differential-resonant (PIDR) control is proposed and high-resolution pulse-width modulation (HRPWM) technology is applied. Finally, a 2-kW bidirectional DC/DC converter prototype is built. According to the experiments, the current ripple is reduced dramatically by 81.5% at full load with the proposed current ripple reduction methods.