Attosecond coherent electron motion in Auger-Meitner decay
Siqi Li, Taran Driver, Philipp Rosenberger, Elio G. Champenois, Joseph Duris, André Al Haddad, Vitali Averbukh, Jonathan C. T. Barnard, N. Berrah, Christoph Bostedt, P. H. Bucksbaum, Ryan Coffee, Louis F. DiMauro, L. Fang, Douglas Garratt, Averell Gatton, Zhaoheng Guo, Gregor Hartmann, Daniel J. Haxton, Wolfram Helml, Zhirong Huang, Aaron LaForge, Andrei Kamalov, Jonas Knurr, Ming‐Fu Lin, Alberto Lutman, James MacArthur, J. P. Marangos, Megan Nantel, Adi Natan, Razib Obaid, Jordan T. O’Neal, Niranjan Shivaram, A. Schori, Peter Walter, Anna L. Wang, Thomas Wolf, Zhen Zhang, Matthias F. Kling, Agostino Marinelli, James Cryan
Abstract
In quantum systems, coherent superpositions of electronic states evolve on ultrafast time scales (few femtoseconds to attoseconds; 1 attosecond = 0.001 femtoseconds = 10 −18 seconds), leading to a time-dependent charge density. Here we performed time-resolved measurements using attosecond soft x-ray pulses produced by a free-electron laser, to track the evolution of a coherent core-hole excitation in nitric oxide. Using an additional circularly polarized infrared laser pulse, we created a clock to time-resolve the electron dynamics and demonstrated control of the coherent electron motion by tuning the photon energy of the x-ray pulse. Core-excited states offer a fundamental test bed for studying coherent electron dynamics in highly excited and strongly correlated matter.