Physics Department - High-harmonic Spectroscopy Probes Lattice Dynamics
Supporting the below United Nations Sustainable Development Goals:支持以下聯合國可持續發展目標：支持以下联合国可持续发展目标：
Abstract
Since the first demonstration of high-order harmonic generation (HHG) from solids in 2010 [1], there have been many works reported HHG from condensed matter and its spectroscopic applications. HHG has been shown first for a variety of materials, including semiconductors, insulators, epsilon-near-zero material, two-dimensional materials and recently topological surface states. In solids, HHG has been used as a probe of electronic properties, including the reconstruction of electronic bandstructure and Berry curvature. In addition, HHG from liquids has been demonstrated and it has a strong potential to probe electronic properties and dynamics of liquids using an all-optical approach. In this talk, we will discuss some emerging opportunities for scientific and industrial applications of high-order harmonic generation from condensed matter. In addition, we will discuss one example where high-harmonic spectroscopy can be used to probe lattice dynamics [2], obtaining both absolute electron-phonon coupling as well as anharmonic phonon-phonon coupling. Our technique is background-free and has extreme sensitivity directly in the energy domain. In combination with the optical deformation potential calculated from density functional perturbation theory and the absolute energy modulation depth, our measurement reveals the maximum displacement of neighboring oxygen atoms in α-quartz crystal to tens of picometres in real space. Our work opens a new realm for the accurate measurement of coherent phonons and their scattering dynamics, which allows for potential benchmarking ab initio calculations in solids.
References
- S. Ghimire et al., Nature Physics, 7, 138–141 (2011).
- J. Zhang et al., Nature Photonics, 18, 792-798 (2024).
Tran Trung Luu received his Master of Science in physics at Korea Advanced Institute of Science and Technology, South Korea; Doctor of Philosophy in physics in Max Planck Institute of Quantum Optics, Germany; ETH Postdoctoral Fellow in ETH Zurich, Switzerland. He has been actively engaged in state-of-the-art research on ultrashort laser pulses and attosecond science. He contributed and played an important role on bringing attosecond science from the gas phase to the condensed phase. Few notable works are the first discovery of a new source of extreme ultraviolet (EUV) light based on the interaction of intense laser pulses and solids; the first demonstration of optical attosecond pulses where the laser pulses are compressed to the limit that they are only half a cycle of the carrier wavelength; the first demonstration of generation of coherent EUV light from liquids and its spectroscopic applications; detection and control of coherent phonons in solids using high-harmonic spectroscopy.
Current Position: Assistant Professor
Highest Education: Ph. D. in Physics, Ludwig Maximilians University of Munich (2015)
Selected Publications:
- “High-harmonic spectroscopy probes lattice dynamics”, Nature Photonics, vol. 18, pp. 792–798, (2024).
- “Noncollinear harmonic spectroscopy reveals crossover of strong-field effects”, Nature Communications, vol. 16, 7660, (2025).
- “Extreme ultraviolet high-harmonic spectroscopy of solids”, Nature, vol. 521, no. 7553, pp. 498- 502, (2015).