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Hot electron dynamics in ultrafast multilayer epsilon-near-zero metamaterials

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Article number165301
Number of pages5
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number16
Publication statusPublished - 6 Apr 2020
Publication typeA1 Journal article-refereed


Realizing remarkable tunability in optical properties without sacrificing speed is critical to obtain all optical ultrafast devices. In this work, we investigate the ultrafast temporal behavior of optically tunable epsilon-near-zero (ENZ) metamaterials, operating in the visible spectral range. To perform this the ultrafast dynamics of the hot electrons is acquired by femtosecond pump-probe spectroscopy and studied based on a two-temperature model (2TM). We show that pumping with femtosecond pulses changes the effective permittivity of the metamaterial by more than 400%. This significant modulation is more pronounced in the ENZ region and we confirm this by the 2TM. The realized ultrafast modulation in effective permittivity, along with the ultrashort relaxation time of 3.3 ps, opens another avenue towards ultrafast photonic applications.

Publication forum classification

Field of science, Statistics Finland