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.

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.

This breakthrough could lead to new insights into various quantum-physical processes, such as chemical reactions and energy transfer in solar cells.

Researchers have developed a novel method to track light fields directly within optical resonators. This enables precise measurements at the exact locations where future field-resolved studies of light-matter interactions will take place.

Scientists from the Department of Physical Chemistry at the Fritz-Haber Institute of the Max Planck Society and the Helmholtz-Zentrum Dresden-Rossendorf have developed a new experimental platform to measure the electric fields of light trapped between two mirrors with precision below a light cycle. These electro-optical Fabry-Pérot resonators allow for precise control and observation of light-matter interactions, particularly in the terahertz (THz) spectral region.

Through the development of a tunable hybrid resonator design and the measurement and modeling of its complex mode spectrum, physicists can now actively switch between nodes and maxima of light waves at relevant resonator locations. This study thus opens new paths for the exploration of quantum electrodynamics and the ultrafast control of material properties.

➀ Researchers at TU Wien have discovered a new physical phenomenon that exists between metals and insulators, which they describe as a 'quantum umbilical cord.';

➁ This phenomenon occurs when the interaction strength between electrons is sufficiently large, leading to additional energy states between metallic and insulating materials;

➂ The discovery opens up new perspectives in material science and technology, suggesting that there are more states between conductors and insulators than previously thought.