High-harmonic probing of electronic coherence in dynamically aligned molecules

We introduce and demonstrate a new approach to measuring coherent electron wave packets using high-harmonic spectroscopy. By preparing a molecule in a coherent superposition of electronic states, we show that electronic coherence opens previously unobserved high-harmonic-generation channels that con...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2013-12, Vol.111 (24), p.243005-243005, Article 243005
Main Authors: Kraus, P M, Zhang, S B, Gijsbertsen, A, Lucchese, R R, Rohringer, N, Wörner, H J
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We introduce and demonstrate a new approach to measuring coherent electron wave packets using high-harmonic spectroscopy. By preparing a molecule in a coherent superposition of electronic states, we show that electronic coherence opens previously unobserved high-harmonic-generation channels that connect distinct but coherently related electronic states. Performing the measurements in dynamically aligned nitric oxide molecules we observe the complex temporal evolution of the electronic coherence under coupling to nuclear motion. Choosing a weakly allowed transition to prepare the wave packet, we demonstrate an unprecedented sensitivity that arises from optical interference between coherent and incoherent pathways. This mechanism converts a 0.1% excitation fraction into a ∼20% signal modulation.
ISSN:0031-9007
1079-7114
DOI:10.1103/physrevlett.111.243005