Quantum Continuum Mechanics Made Simple

Giovanni Vignale, Jianmin Tao, Gao Xianlong +1 more

J. J. Yeh, Joseph H. Eberly

Abrupt radiative excitation into a one-electron atomic continuum of distinct zero-width energy levels is investigated in a simple energy-conservative atomic model. Induced off-diagonal coherence is shown to decay irreversibly. That is, it is shown that one cannot recover off-diagonal coherence by the application of subsequent radiative pulses, ruling out the occurrence of long-time or repetitive coherent transients such as photon echoes in this model of continuum transitions. A brief comparison with the case of transitions in a Doppler-broadened continuum, where coherent transients are commonly observed, is made.

Heng Xiao

Stig Stenholm, Asta Paloviita

We consider the time evolution of a discrete state embedded in a continuum. Results from scattering theory can be utilized to solve the initial value problem and discuss the system as a model of wave packet preparation. Extensive use is made of the analytic properties of the propagators, and simple model systems are evaluated to illustrate the argument. We verify the exponential appearence of the continuum state and its propagation as a localized wave packet.

Charles E. Burkhardt, Jacob J. Leventhal

Stig Stenholm, Asta Paloviita

We consider the time evolution of a discrete state embedded in a continuum. Results from scattering theory can be utilized to solve the initial value problem and to discuss the system as a model of wave packet preparation. Extensive use is made of the analytic properties of the propagators, and simple model systems are evaluated to illustrate the argument. We verify the exponential appearence of the continuum state and its propagation as a localized wave packet.