Obtaining insight into microscopic cooperative effects is a fascinating topic in condensed matter research since through self-coordination and collectivity, they can lead to instabilities with macroscopic impacts like phase transitions. We use femtosecond time- and angle-resolved photoelectron spectroscopy (trARPES) to optically pump and probe TbTe3, an excellent model system to study these effects. We drive a transient CDW melting, excite collective vibrations in TbTe3, and observe them through their time-, frequency-, and momentum-dependent influence on the electronic structure. We are able to identify the role of the observed collective vibration in the transition and to document the transition in real time. The information we demonstrate is accessible with trARPES will greatly enhance the understanding of all materials exhibiting collective phenomena.
The original publication is available at link DOI:10.1126/science.1160778