We study how the multi-channel Kondo effect is dynamically induced to affect the photoemission and the inverse photoemission spectrum when an electron is emitted from (or added to) the completely screened Kondo impurity with spin $S>1/2$. The spectrum thereby shows a power-law edge singularity characteristic of the multi-channel Kondo model. We discuss this anomalous behavior by using the exact solution of the multi-channel Kondo model and boundary conformal field theory. The idea is further applied to the photoemission for quantum spin systems, in which the edge singularity is controlled by the dynamically induced overscreening effect with a mobile Kondo impurity.

6 pages, 4 figures, submitted to PRB