Ultrafast electron dynamics in phenylalanine initiated by attosecond pulses

This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science on Volume 346, 17 october 2014, DOI: 10.1126/science.1254061.
In the past decade, attosecond technology has opened up the investigation of ultrafast electronic processes in atoms, simple molecules, and solids. Here, we report the application of isolated attosecond pulses to prompt ionization of the amino acid phenylalanine and the subsequent detection of ultrafast dynamics on a sub-4.5-fs temporal scale, which is shorter than the vibrational response of the molecule. The ability to initiate and observe such electronic dynamics in polyatomic molecules represents a crucial step forward in attosecond science, which is progressively moving toward the investigation of more and more complex systems
We acknowledge the support from the European Research Council under the ERC grants no. 227355 ELYCHE and 290853 XCHEM, from LASERLAB-EUROPE (grant agreement no. 284464, EC's Seventh Framework Programme), from European COST Action CM1204 XLIC, the MICINN Project FIS2010-15127, the ERA-Chemistry Project PIM2010EEC-00751, the European Grants MC-ITN CORINF and MC-RG ATTOTREND 268284, the UK’s STFC Laser Loan Scheme, the Engineering and Physical Sciences Research Council (grant EP/J007048/1), the Leverhulme Trust (grant RPG-2012-735), and the Northern Ireland Department of Employment and Learning