【摘要】 应用Weisskopf-Wigner理论研究电荷量子比特与声子库耦合系统的时间演化,讨论声子库的初态对整个耦合系统的影响。研究结果表明:假定初始时刻电荷量子比特处于激发态并且与声子库共振,当声子库初始为真空态时,其演化性质类似于二能级原子的自发辐射;当声子库初始为粒子数态时,其基态和激发态的概率幅分别具有余弦求和与正弦求和的形式。更多还原

【Abstract】 The time evolution of the state vector for the coupled system that a Josephson charge qubit is coupled to the phonon reservior is investigated by using the Weisskopf-Wigner theory,and the influence of the initial states of the phonon reservior on the coupled system is discussed.The result shows that one assume that at time t=0 the Josephson charge qubit is in the excited state and in resonance with the phonon reservior,when the initial state of the bath is the vacuum state,its evolution properties are the same as the spontaneous emission of the two-level atom.And when the initial state of the environment is the number states,the probability amplitude of it’s ground state and excited state is the cosine’s summation form and the sine’s summation form respectively.更多还原