Hosted on MSN2mon
An unexpected delay in a standard quantum optical process generates pairs of photons
(Feynman diagram calculations rely heavily on perturbation ... increasingly complicated type of SPDC photon scattering. The lowest-order is basic—a pump photon scatters into a pair of lower ...
Hosted on MSN1mon
A new calculation of the electron's self-energy improves determination of fundamental constants
The effect was first detected by Willis Lamb and Robert Retherford in 1947, with the emitted photon having a frequency ... and it's easiest via Feynman diagrams. "Two-loops" refers to the Feynman ...