<p>The ultrafast dynamics and interactions of electrons in solids have been a challenge to observe directly. Researchers from the University of Oldenburg and Politecnico di Milano have developed a new spectroscopic method that uses ultra-short laser pulses to analyze the movement of electrons in materials. This method, known as two-dimensional electronic spectroscopy (2DES), allows for the study of quantum-physical processes with high temporal resolution. The team has found a way to simplify the experimental implementation of this procedure, making it more accessible for wider use.</p><p>The research involves using a sequence of three ultrashort laser pulses to excite electrons in a material, changing its optical properties, and then using a third pulse to provide information about the excited system. By varying the time intervals between these pulses, different stages of the process can be observed. The team's new approach, which involves adding an optical component to an interferometer, has significantly improved the precision of the laser pulses.</p><p>This breakthrough could lead to new insights into various quantum-physical processes, such as chemical reactions and energy transfer in solar cells.</p>