American Journal of Physics
Spin and photon echoes
D. C. Haueisen, Thomas D. Bonifield
Abstract
The classical interpretation of the spin echo is reviewed, followed by a simple quantum-mechanical derivation of the general echo phenomenon for a two-state system. The photon echo is then examined, and graphs of hydrogenic wave functions for eigenstates and transitional states are shown as examples. As many as possible of the classical notions associated with the spin echo are applied to the case of photon echoes.