Attosecond tracking of light absorption and refraction in fullerenes

TL;DR

This paper demonstrates attosecond-scale tracking of the emergence of collective excitations in fullerenes, revealing transient features in light absorption and refraction relevant for ultrafast photonics.

Contribution

It introduces a combined quantum chemical and kinetic approach to observe real-time collective mode formation in finite systems.

Findings

Identification of transient features in light absorption and refraction

Analytical model explaining the numerical results

Proposal for attosecond metrology to measure these effects

Abstract

The collective response of matter is ubiquitous and widely exploited, e.g. in plasmonic, optical and electronic devices. Here we trace on an attosecond time scale the birth of collective excitations in a finite system and find distinct new features in this regime. Combining quantum chemical computation with quantum kinetic methods we calculate the time-dependent light absorption and refraction in fullerene that serve as indicators for the emergence of collective modes. We explain the numerically calculated novel transient features by an analytical model and point out the relevance for ultra-fast photonic and electronic applications. A scheme is proposed to measure the predicted effects via the emergent attosecond metrology.