Cover story: Femtosecond pump-probe spectroscopy serves as an atomic-scale "ultra-slow-motion camera" with femtosecond temporal resolution, enabling the direct observation of coherent phonon dynamics in two-dimensional van der Waals semiconductors. This technique captures key processes such as electron–phonon coupling, interlayer energy transfer, and dimensionally confined lattice vibrations, offering profound insights into ultrafast dynamics in low-dimensional materials. Beyond advancing fundamental understanding, it opens new avenues for the coherent control of quantum phenomena and the development of next-generation ultrafast optoelectronic and quantum information devices.

Nie, X.; Zheng, J.; Gao, X. Coherent Phonon Dynamics in 2D van der Waals Semiconductors. Low-Dimensional Materials 2025, 1(1), 2.