Dortmund, Germany – May 2025 — Researchers at TU Dortmund University, in collaboration with colleagues from the University of Paderborn and the University of Nottingham, have pioneered a novel optical method capable of detecting exceptionally minute atomic displacements within crystalline solids. This breakthrough, recently published in Nature Materials, represents a significant advancement in the real-time observation of ultrafast processes in matter.
In solid-state systems, atomic motion typically occurs on timescales of femtoseconds (10⁻¹⁵ seconds) and at distances less than the diameter of an atom. Capturing such rapid and minuscule movements presents formidable technical challenges. The team led by Professor Martina Hentschel and Dr. Dirk Englund has overcome these challenges by utilizing a sophisticated interferometric technique based on the interaction of laser light with lattice vibrations.
Their approach leverages quantum interference of electronic excitations within the material, enabling the detection of vibrational amplitudes in the sub-picometer range. By analyzing the resulting spectral modulations in reflected probe light, the researchers could track the onset and evolution of coherent phonons—quantized lattice vibrations—induced by ultrashort laser pulses.
This technique not only provides a new window into the dynamics of condensed matter but also establishes a framework for investigating energy transfer, phase transitions, and non-equilibrium states in a wide range of materials. It holds promise for applications in semiconductor physics, quantum computing, and the development of novel optoelectronic devices.
The study showcases how advances in ultrafast optics can serve as powerful diagnostic tools for materials science, offering insights previously inaccessible with conventional methods. The researchers emphasize that their method is broadly applicable and can be adapted for various material classes, including semiconductors, insulators, and complex oxides.
The findings underscore the value of interdisciplinary collaboration and cutting-edge photonic instrumentation in addressing fundamental questions about matter at the atomic scale.