Measuring the quantum state of photoelectrons
Journal article, 2025
A photoelectron, emitted due to the absorption of light quanta as described by the photoelectric effect, is often characterized experimentally by a classical quantity, its momentum. However, since the photoelectron is a quantum object, its rigorous characterization requires the reconstruction of the complete quantum state, the photoelectron's density matrix. Here, we use quantum state tomography to fully characterize photoelectrons emitted from helium and argon atoms upon absorption of ultrashort, extreme ultraviolet light pulses. While in helium we measure a pure photoelectronic state, in argon, spin-orbit interaction induces entanglement between the ion and the photoelectron, leading to a reduced purity of the photoelectron state. Our work shows how state tomography gives new insights into the fundamental quantum aspects of light-induced electronic processes in matter, bridging the fields of photoelectron spectroscopy and quantum information, and offering new spectroscopic possibilities for quantum technology.
photoelectron
quantum tomography
spectroscopy
quantum information
quantum physics
attosecond physics
Author
Hugo Laurell
Lund University
Lawrence Berkeley National Laboratory
Sizou Luo
Lund University
Robin Weissenbilder
Lund University
Mattias Ammitzböll
Lund University
Shahnawaz Ahmed
Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
Hugo Söderberg
Lund University
C. Leon. M. Petersson
AlbaNova University Center
Vénus Poulain
Lund University
Chen Guo
Lund University
Christoph Dittel
University of Freiburg
Daniel Finkelstein-Shapiro
Universidad Nacional Autónoma de México
Richard Squibb
University of Gothenburg
Raimund Feifel
University of Gothenburg
Mathieu Gisselbrecht
Lund University
Cord L. Arnold
Lund University
Andreas Buchleitner
University of Freiburg
Eva Lindroth
Stockholm University
Anton Frisk Kockum
Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
Anne L’Huillier
Lund University
Nature Photonics
1749-4885 (ISSN) 17494893 (eISSN)
Vol. 19 5042Roots
Basic sciences
Subject Categories (SSIF 2011)
Atom and Molecular Physics and Optics
Condensed Matter Physics
DOI
10.1038/s41566-024-01607-8
Related datasets
Mätning av fotoelektroners kvanttillstånd [dataset]
DOI: https://doi.org/10.5878/m4fc-9a58