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 [2-7] . HHG has been shown first for a variety of materials, including semiconductor, insulator, 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 [8] and it has a strong potential to probe electronic properties and dynamics of liquids using 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.

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 and currently appointed as Assistant Professor in Physics in The University of Hong Kong. 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. He has received numerous awards/honors for his studies as well as for his pioneering research including Physics Olympiad, Young Researcher Awards, prestigious fellowships from ERC Marie Currie, ETH Zurich, Canadian FRQNT and others.

[1] Ghimire, S., et al., Observation of high-order harmonic generation in a bulk crystal. Nature Physics, 2010. 7(2): p. 138-141.
[2] Schubert, O., et al., Sub-cycle control of terahertz high-harmonic generation by dynamical Bloch oscillations. Nature Photonics, 2014. 8(2): p. 119-123.
[3] Luu, T.T., et al., Extreme ultraviolet high-harmonic spectroscopy of solids. Nature, 2015. 521(7553): p. 498-502.
[4] Ndabashimiye, G., et al., Solid-state harmonics beyond the atomic limit. Nature, 2016. 534(7608): p. 520-3.
[5] Liu, H., et al., High-harmonic generation from an atomically thin semiconductor. Nature Physics, 2016. 13(3): p. 262-265.
[6] Yoshikawa, N., T. Tamaya, and K. Tanaka, High-harmonic generation in graphene enhanced by elliptically polarized light excitation. Science, 2017. 356(6339): p. 736-738.
[7] Bai, Y., et al., High-harmonic generation from topological surface states. Nature Physics, 2020.
[8] Luu, T.T., et al., Extreme-ultraviolet high-harmonic generation in liquids. Nat Commun, 2018. 9(1): p. 3723.

Please contact phweb@ust.hk should you have questions about the talk.