Tencent Meeting: 992-421-636，密码：0422

Abstract:
Strong field physics gives rise to a variety of phenomena, ranging from coherent electron diffraction to attosecond soft X-ray emission [1]. We have, over the years, developed intense sources of waveform-controlled mid-IR light [2] to exploit aspects such as the ponderomotive scaling, quantum diffusion, and quasi-static photoemission. I will describe how we generate isolated attosecond pulses in the soft X-ray water window [3] across the oxygen edge up to 600 eV below the atomic unit of time [4]. Furthermore, I will explain how attosecond soft X-ray science can provide an entirely new angle on real-time quantum many-body dynamics [5]. I will describe applications that address some of the most intricate challenges in contemporary physics, such as phase transitions [6] in solids [7] and molecular science [8]. Recent investigations pursue new ways to detect classical and quantum correlations in those interactions [9].

[1] B. Wolter et al. Phys. Rev. X 5, 021034 (2015).
[2] U. Elu et al. Nature Phot.on 15, 277-280 (2021).
[3] S. M. Teichmann et al. Nature Commun. 7, 11493 (2016).
[4] F. Ardana-Lamas et al. Ultrafast Science, 10, 34133 (2025).
[5] T.P.H. Sidiropoulos et al. Nature Comm. 14, 7407 (2023).
[6] I. Tyulnev et al. Commun. Mat. 6, 152 (2025).
[7] T.P.H. Sidiropoulos et al. Phys. Rev. X. 11, 041060 (2021).
[8] S. Severino et al. Nature Photon. 18, 731-737 (2024).
[9] D. Theidel et al. PRX Quantum, 5, 040319 (2024).

About the speaker:
Biegert received his PhD in Physics in 2001 from the Technische Universität München, based on work at the University of New Mexico in the USA under the supervision of Jean-Claude Diels. The topic of his PhD was the physics of multiphoton coherent excitation of atomic sodium, with applications for astronomical guidestars. After completing his PhD, he pursued his Habilitation to lead a group on attosecond science at ETH Zürich. Since 2007, at ICFO, he has pioneered mid-IR photonics, attosecond soft X-rays, and laser-induced electron diffraction, leading to breakthroughs in imaging chemical dynamics and carrier motion in quantum materials. Currently, he coordinates a European Commission FET Consortium and participates in two additional FET consortia. Jens Biegert is a Guest Professor at the Fritz Haber Institute of the Max Planck Society in Berlin. For example, he is actively involved in the scientific community as a co-author of the white book with Gérard Mourou, which contributed to the development of the 1.2-billion-Euro European Extreme Light Infrastructure. He serves on the Board of Directors of OPTICA, is Chair of the Meetings Council, and is part of the Strategic Planning and Finance Councils. He previously served on the Board of Chairs of ARIE, the Analytical Research Infrastructures of Europe, which represents sevennetworks of European infrastructures involving 40,000 researchers. He led Europe’s foremost laser network, “Laserlab-Europe,” as its Executive Director, uniting 46 leading research infrastructures across 22 European countries. He is a Topical Editor of OPTICA and AAAS/CAS Ultrafast Science, and is a Fellow of the Studienstiftung des deutschen Volkes, OPTICA, DAAD and the American Physical Society. He has received numerous awards, including the Thousand Talents Program Award of the People‘s Republic of China, the OSA Allen Prize, the Bessel Prize of the Humboldt Foundation, the ERC Advanced Grant, two ERC Proof of Concept Grants. He recently received the C.E.K. Mees Medal from OPTICA and is an Elected Member of the Academia Europaea, Europe’s Academy of Sciences.

Inviter: 魏志义 研究员

Contact: 杨翠 cuiyang@iphy.ac.cn