On April 16, 2026, Professor Anne L'Huillier, the 2023 Nobel Prize laureate in Physics from Lund University, visited Zhiyuan College, marking her first trip to China and her first academic lecture in the country. The event was hosted by Professor He Feng, Executive Deputy Dean of Zhiyuan College.
In her lecture titled "A Fleeting Moment: The Path of Attoseconds," Prof. L'Huillier delivered a systematic explanation of electron dynamics on attosecond timescales. She noted that electron motion within atoms and molecules occurs in this extremely brief temporal window. The generation of attosecond pulses has, for the first time, enabled humanity to probe such ultrafast processes.
She reviewed the development of high-order harmonic generation (HHG), explaining its core physical mechanism: electrons escape via tunneling ionization under a strong laser field, are accelerated in the field, and then recombine with their parent ion, releasing high-energy photons. This process repeats every half-cycle of the laser field, generating a train of attosecond pulses. Prof. L'Huillier emphasized that understanding this phenomenon requires the framework of strong-field physics, as it lies beyond traditional perturbation theory.
The lecture further covered the generation and measurement of isolated attosecond pulses. By superimposing phase-locked high-order harmonics, extremely short attosecond light pulses can be synthesized. Advanced interferometric techniques, such as RABBITT, allow researchers to extract photoionization phase information and measure time delays in the photoemission process. These breakthroughs have enabled "time-resolved imaging" of electron dynamics, moving beyond energy measurements to capture quantum phase and propagation time.
During a "Dialogue with the Master" session, faculty and students engaged enthusiastically on topics including the future of attosecond science, experimental challenges, and interdisciplinary applications. Prof. L'Huillier shared insights from her own research career, emphasizing the vital importance of long-term collaboration, close interaction between theory and experiment, and resilience in scientific pursuit. She encouraged young researchers to join this emerging field.
Following the lecture, Prof. L'Huillier visited the Zhiyuan students' dormitory for an in-depth "Exchange & Discourse" session. In a relaxed setting, she discussed topics ranging from the symmetry-determined generation of odd harmonics and the impact of artificial intelligence on research, to career choices, learning strategies, and maintaining work-life balance.
At the conclusion of the events, Prof. He presented Prof. L'Huillier with an honorary certificate and commemorative gifts on behalf of Zhiyuan College. The college also presented her with a piece of Chinese calligraphy reading "Da Dao Zhi Yuan" (The Great Path Leads to Lofty Heights), honoring her spirit of dedicated scholarship.
For the students of Zhiyuan College, Prof. L'Huillier's words planted seeds of passion and curiosity, inspiring them to explore the frontiers of science with resilience and an unceasing quest for knowledge.