A new quantum clock for measuring photoemission delay times
Year: 2019
Type: preprint
Abstract: The age of attosecond physics was ushered in by the invention of methods for probing phenomena on a time scale less than femtoseconds [F. Krausz, M. Ivanov, Rev. Mod. Phys. 81, 163 (2009)]. In photoemission, the Eisenbud-Wigner-Smith (EWS) time delay [R. Pazourek, S. Nagele, J. Burgdorfer, Rev. Mod. Phys. 87, 765 (2015)] is the interval between photon annihilation and emission of the electron, usually measured in attoseconds ($10^{-18}$ seconds), and varies with the kinetic energy and the angle of emission of the electron wave packet. We present a new interferometric method of measurement, using two phase-locked Extreme Ultraviolet pulses of frequency $\omega$ and $2\omega$, from a Free-Electron Laser. Phase differences between one- and two-photon ionization channels are extracted, and used to derive the relative EWS delay for one- and two-photon ionization of neon as a function of emission angle. Agreement with theory is excellent. Competing techniques require the use of an IR field, which necessitates corrections, but our method is correction-free. This new quantum clock is a powerful tool for investigating ultrafast processes in atoms and molecules.
Source: arXiv (Cornell University)
Authors: Daehyun You, Kiyoshi Ueda, Elena V. Gryzlova, Alexei N. Grum-Grzhimailo, Maria M. Popova, Ekaterina I. Staroselskaya, Oyunbileg Tugs, Yuki Orimo, Takeshi Sato, Kenichi L. Ishikawa, Paolo Carpeggiani, Tamás Csizmadia, Miklós Füle, G. Sansone, Praveen Kumar Maroju, A. D’Elia, Tommaso Mazza, Michael Meyer, Carlo Callegari, Michele Di Fraia, Oksana Plekan, Robert Richter, L. Giannessi, E. Allaria, G. De Ninno, M. Trovó, L. Badano, B. Diviacco, David Gauthier, Najmeh Mirian, G. Penco, Primož Rebernik Ribič, S. Spampinati, C. Spezzani, G. Gaio, Kevin C. Prince
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2965567896