Time: 14:30 p.m. (Friday, January 15, 2021)
Host: Prof. Qing Dai (戴庆研究员)
You are all welcome!
Brief introduction of the speaker：
Javier García de Abajo is an expert in the science of light and its interaction with atoms, molecules, and nanostructures. He maintains an intense research agenda covering a wide range of topics and involving an extended network of collaborators in the fields of surface science, physical chemistry, electron microscopy, plasmonics, and nanophotonics. He heads the Nanophotonics Theory Group at ICFO-The Institute of Photonic Sciences, with an output of about 20 papers per year in prestigious journal.Through seminal theoretical works, he has predicted and explained new phenomena that include collective electron excitations–plasmons–in atomic scale systems such as molecules and nanographenes; complete optical absorption by atomic layers; ultrasfast electron-beam interactions with localized optical fields; strong coupling between molecules and localized optical resonances; ultrafast radiative heat transfer; and others.
García de Abajo’s work is well cited (30000+ citation, h index of 90, WoK data) and widely visible at international conferences (200+ invited talks, including 30+ keynotes and 12 plenaries). He has 400+ publications in refereed international journals, of which 2 in Reviews of Modern Physics, 4 in Nature, 4 in Science, 2 in Chemical Society Reviews, 3 in Nature Materials, 2 in Nature Nanotechnology, 2 in Nature Photonics, 3 in Nature Physics, 9 in Nature Commun. , 41 in Physical Review Letters, 2 in Science Advances, 3 in Advanced Materials, 5 in Light: Sci. & Appl., 16 in ACS Nano, and 40 in Nano Letters. He is a Fellow of the Optical Society of America and the American Physical Society.
In this presentation, we will start by reviewing recent advances in high-harmonic generation (HHG) in solids and discuss graphene as a material that is particularly suited to produce strong nonlinear response at mid-infrared fundamental frequencies. Experiments and theoretical analyses will be discussed in a tutorial fashion, as well as some physical limits in the achievable nonlinear energy conversion. In general, materials with highly non-parabolic electron dispersion offer great potential for HHG at those excitation energies, which we will illustrate with a simple order-of-magnitude estimate applicable to a vast range of materials. We will also discuss the ability of electron beams to interact with nonlinear fields and probe them with high efficiency to obtain insight into the nonlinear optical response at the nanometer scale in combination with ultrafast optical illumination. We will conclude by examining the prospects for single and multiple low-energy free electrons to trigger high-harmonic response in nanomaterials.