Facultad de Ciencias

The route towards manipulation of the electrical properties of matter beyond the current limit of electronics starts from a comprehensive study of ultrafast dynamics initiated in matter by interaction with light [1]. In this respect, strong-filed interactions initiated by a relatively intense infrared (IR) few-femtosecond pulse (peak intensity ~10¹² W/cm²) are still little explored and understood [2]. In order to access this unexplored region, we combined attosecond transient reflection spectroscopy (ATRS) with simultaneous attosecond streaking measurement to obtain a precise calibration of the pump electric field and access the exact timing of the physical phenomena at play. In tandem with theoretical calculations, this allowed us to study ultrafast exciton dynamics in a wide-bandgap insulator like MgF₂ [3], and to disentangle the complex photoinjection mechanism in a prototypical semiconductor like Ge. Thanks to the extreme temporal resolution of our measurements, our findings shed new light onto optical manipulation of carriers in dielectrics close to the petaHertz domain.

[1] H.J. Caulfield, S. Dolev, Nature Photonics 4, 261 (2010).

[2] R. Borrego-Varillas, M. Lucchini & M. Nisoli, Reports on Progress in Physics 85, 066401 (2022)

[3] M. Lucchini, S. A. Sato, G. D. Lucarelli, B. Moio, G. Inzani, R. Borrego-Varillas, F. Frassetto, L. Poletto, H. Hübener, U. De Giovannini, A. Rubio & M. Nisoli, Nature Communications 12, 1021 (2021)