2025/02/18(Tue)
10:30 -11:30
一樓演講廳 1F, Auditorium
視訊演講 Video Seminar [ Meeting Link / ID: 2512 930 2351 / Password: 2Vqr49Eh8pQ ]
- 實體與視訊演講同時進行。
- Both physical and virtual are available.
Title
Exploring Ultrafast Carrier Dynamics and Phase Transitions in Layered Quantum Materials via Tr-ARPES
Speaker
林秉慧助研究員 (國家同步輻射研究中心) Dr. Ping-Hui Lin (Condensed Matter Physics Group, National Synchrotron Radiation Research Center)Abstract
Understanding ultrafast carrier dynamics is crucial for revealing many-body interactions and emergent phenomena in quantum materials. Time-resolved angle-resolved photoemission spectroscopy (Tr-ARPES) is considered a powerful technique for probing non-equilibrium electronic processes with high temporal and momentum resolution. Recent advancements in high harmonic generation (HHG)-based ultrafast spectroscopy have enabled precise investigations of carrier relaxation pathways in layered materials.
Fluence-dependent electronic relaxation pathways in graphite have been observed, bridging static and dynamic quasi-equilibrium states. The results highlight the interplay between electron-electron and electron-phonon interactions in dictating carrier relaxation timescales.
Furthermore, the charge density wave (CDW) phase transition in TiSe2 has been explored, revealing orbital-selective carrier relaxation and effective mass renormalization. The findings suggest that transition metal d-states play a significant role in CDW formation, while transient band structure analysis under varying excitation fluences provides evidence for a multi-stage CDW melting and recovery process.
These findings contribute to a broader understanding of phase transitions and non-equilibrium quantum states in strongly correlated materials. The capabilities of Tr-ARPES in uncovering fundamental interactions in layered quantum materials underscore its potential for advancing ultrafast phase control in condensed matter systems.
Language
演講語言 (Language): in English