To catch and smash charge on the hop

• Published in: Science (American Association for the Advancement of Science) Vol. 350; no. 6262; pp. 740 - 741
• Main Author: Ueda, Kiyoshi
• Format: Journal Article
• Language: English
• Published: Washington American Association for the Advancement of Science 13.11.2015; The American Association for the Advancement of Science
• Subjects: Cations; Charge; Charge transfer; Correlation; Couples; Dynamical systems; Dynamics; Electron transfer reactions; Femtosecond; Migration; PERSPECTIVES; Photocatalysis; Photosynthesis
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aad3982

High-harmonic spectroscopy can probe charge migration controlled by a laser field [Also see Report by Kraus et al . ] Charge transfer plays a central role in photosynthetic and photocatalytic reactions and has thus been studied extensively in a wide range of systems. Generally, charge transfer is considered to be driven by the nuclear dynamics; nuclear motion in the system couples with electron motion and causes charge transfer. Two decades ago, ultrafast charge transfer was reported in isolated peptide cations ( 1 ); a theoretical demonstration that charge can migrate from one side to the other in polyatomic molecules without nuclear motion, due solely to electron correlations, soon followed ( 2 ). To differentiate electron correlation-driven processes from nuclear dynamics-driven ones, the term charge migration was introduced. Electron correlation-driven charge migration is faster than nuclear motion and occurs within femtoseconds, and is one of the most important subjects in attosecond science ( 3 ). The first report offering evidence of charge migration appeared in 2014 ( 4 ). On page 790 of this issue, Kraus et al. ( 5 ) describe the most advanced approach to probe attosecond charge migration and how to control it.