What is ARPES?

In ARPES, a soft-xray photon from the synchrotron is focussed onto the sample, generating a distribution of photoelectrons in energy and angle. It is important that the photons are monochromatic, so that the energy and angle of the electrons can be converted into the energy and momentum of the electrons in the solid.

The movie shows how the electrons are collected by a lens, and dispersed between two hemispheres onto a detector. The photolectrons are imaged by the detector in real-time, giving a small piece of the overall electronic bandstructure.