Information
This seminar serves as a pre–event for a Junior Research Program Tohoku Forum for Creativity, “X–ray Spectroscopy for Future Nano Materials Science” which will be organized in 2026 by International Center for Synchrotron Radiation Innovation Smart, Tohoku University.
Date
Tuesday, November 25, 2025, 09:00 – 10:00 (JST)
Venue
SRIS Building, Entrepreneur Hall, Tohoku University [Access]
Hosted by
International Center for Synchrotron Radiation Innovation Smart, Tohoku University
Tohoku Forum for Creativity, Organization for Research Promotion, Tohoku University
Speaker
Prof. Dr. Hans Jakob Wörner (Laboratory of Physical Chemistry, ETH Zürich)
Time Schedule
- 09:00 – 10:00
- Hans Jakob Wörner (Laboratory of Physical Chemistry, ETH Zürich)
- Advancing attosecond science to liquids and chiral molecules
Abstract
Attosecond science is maturing into a transformative tool for measuring and understanding ultrafast electronic and structural dynamics, but its extension to complex systems is hampered by challenges of both technical and fundamental nature. Our group has pioneered attosecond spectroscopy in liquids. Attosecond photoelectron spectroscopy with liquid microjets has been developed and applied to measure delays of 50–70 attoseconds between the photoemission from liquid vs. gas–phase water¹. Detailed modelling has revealed that the delays are dominated by the influence of the first two solvation shells on the photoionization dynamics. This interpretation has been confirmed by attosecond photoelectron spectroscopy of size–resolved water clusters², which showed that the photoionization delays reflect the spatial delocalization of the electronic wavefunctions, which grows with the cluster size from monomers to tetramers but then saturates at a typical extension of 4–5 molecules². In parallel, soft–X–ray absorption spectroscopy with attosecond pulses has been developed, first in gases³ and then in liquids⁴, enabling element–specific studies of solvated molecules in liquid water. This novel technique has been used to reveal the electronic and structural dynamics underlying ultrafast proton transfer in solvated urea⁵ and the dephasing of conical–intersection–driven electronic dynamics in solvated pyrazine⁶. To date, spectroscopy with attosecond pulses has been missing the ability to distinguish chiral molecules, because of a lack of circularly polarized attosecond pulses. We have developed attosecond metrology in circular polarization⁷ and applied it to the study of continuum–continuum transitions in electron vortices, establishing a general framework for attosecond circular–dichroism chronoscopy⁸. The first application of circularly polarized attosecond pulses to chiral–sensitive experiments enabled us to observe and control photoelectron circular dichroism (PECD) on the attosecond timescale and to directly measure chiral photoionization delays of up to ~240 attoseconds⁹. These advances chart a promising path for attosecond–resolved studies of molecular function in aqueous environments, opening exciting opportunities for understanding radiation damage, solvation dynamics, and chiral interactions at their fundamental electronic timescale.
References: [1] I. Jordan et al. Science 369, 974 (2020) [2] X. Gong, et al, Nature 609, 507 (2022) [3] A. Smith, et al, JPCL 11, 1981 (2020) [4] Y. Pertot et al, Science 355, 264 (2017) [5] Z. Yin et al. Nature 619, 749 (2023) [6] Y.P Chang, et al, Nat. Phys., 21, 137 (2025) [7] M. Han et al. Optica 10, 1044 (2023), [8] M. Han et al. Nat. Phys. 19, 230 (2023) [9] M. Han et al. Nature 645, 95 (2025)
Poster
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