title: Quantum coherence controls the charge separation in a prototypical artificial light-harvesting system.
abstract: The efficient conversion of light into electricity or chemical fuels is a fundamental challenge. In artificial photosynthetic and photovoltaic devices, this conversion is generally thought to happen on ultrafast, femto-to-picosecond timescales and to involve an incoherent electron transfer process. In some biological systems, however, there is growing evidence that the coherent motion of electronic wavepackets is an essential primary step, raising questions about the role of quantum coherence in artificial devices. Here we investigate the primary charge-transfer process in a supramolecular triad, a prototypical artificial reaction centre. Combining high time-resolution femtosecond spectroscopy and time-dependent density functional theory, we provide compelling evidence that the driving mechanism of the photoinduced current generation cycle is a correlated wavelike motion of electrons and nuclei on a timescale of few tens of femtoseconds. We highlight the fundamental role of the interface between chromophore and charge acceptor in triggering the coherent wavelike electron-hole splitting.
authors.affiliation: Istituto Nanoscienze-CNR, Modena, Italy.
authors.forename: Carlo Andrea
authors.initials: CA
authors.lastname: Rozzi
authors.forename: Sarah Maria
authors.initials: SM
authors.lastname: Falke
authors.forename: Nicola
authors.initials: N
authors.lastname: Spallanzani
authors.forename: Angel
authors.initials: A
authors.lastname: Rubio
authors.forename: Elisa
authors.initials: E
authors.lastname: Molinari
authors.forename: Daniele
authors.initials: D
authors.lastname: Brida
authors.forename: Margherita
authors.initials: M
authors.lastname: Maiuri
authors.forename: Giulio
authors.initials: G
authors.lastname: Cerullo
authors.forename: Heiko
authors.initials: H
authors.lastname: Schramm
authors.forename: Jens
authors.initials: J
authors.lastname: Christoffers
authors.forename: Christoph
authors.initials: C
authors.lastname: Lienau