Übergangsamplitude

Übergangsamplitude refers to a concept in quantum mechanics that describes the probability amplitude for a quantum system to transition from one specific state to another. It is a complex number whose absolute square gives the probability of this transition occurring. This amplitude is fundamental to understanding how quantum systems evolve over time and interact with their environment.

The calculation of Übergangsamplitude is often performed using perturbation theory, especially when the interaction causing the transition is weak. In such cases, the amplitude can be expressed as a sum of terms, each representing a different pathway or order of interaction. These amplitudes are crucial in predicting the outcomes of scattering experiments, the rates of radioactive decay, and the frequencies of emitted or absorbed photons in atomic and molecular transitions.

The time-dependent Schrödinger equation governs the evolution of quantum states and is the basis for calculating Übergangsamplitude. By solving this equation for a system subjected to a time-dependent perturbation, one can determine the probability amplitudes for transitions between different energy levels. The concept is a cornerstone for understanding phenomena like resonant absorption and stimulated emission in lasers, as well as the dynamics of quantum entanglement.