Title: Beyond-dipole Maxwell-TDDFT for Nanoplasmonics, Realistic Cavities, Optical Vortices and Beyond
When: Tuesday, September 17, 2024, 12:00
Place: Department of Theoretical Condensed Matter Physics, Faculty of Sciences, Module 5, Seminar Room (5th Floor)
Speaker: Franco P. Bonafé, MPI for Structure and Dynamics of Matter, Hamburg, Germany.
Numerous open questions in condensed matter physics and spectroscopy demand a careful treatment of light-matter interactions with structured light and with local fields in complex electromagnetic environments. Aiming for an atomistic, ab-initio description, some of these problems can be treated within standard mean-field time-dependent density-functional theory (TDDFT), while the radiative dynamics has to be done in a self-consistent Maxwell-TDDFT framework, as a mean-field QED method [1]. In both cases, a beyond-electric-dipole approach is needed to include all relevant effects. In this seminar, I will present both methodological aspects as well as new applications of beyond-dipole light-matter interactions without multipolar truncations. Namely, the extension of the Maxwell-TDDFT method using full minimal coupling, as implemented in the open-source Octopus code [2], and the novel effects that can be captured in a variety of physical scenarios will be explained. Among the applications, Cherenkov radiation from an electronic wavepacket with back-reaction, magneto-optical effects in non-chiral systems with non-chiral light, and the corrections to plasmonic modes in nanoparticle dimers [3], will be discussed. Furthermore, high-harmonic generation using light with orbital angular momentum, also called optical vortices will be introduced, where beyond-dipole signatures are captured both in the incident and the emitted radiation [4]. Then, I will briefly introduce the coupling of Maxwell equations with time-dependent density functional tight-binding (TDDFTB) [5] as a way to reach picosecond timescales in realistic cavity structures which can be obtained by inverse electromagnetic design. Finally, outlooks on the ab-initio investigations of the mechanism behind light scattering in tip-enhanced spectra [6] will be mentioned.
References
- R. Jestädt, M. Ruggenthaler, M.J.T. Oliveira, A. Rubio, and H. Appel. Adv. Phys. 68:4, 225 (2019)
- N. Tancogne-Dejean, M.J.T. Oliveira, et al. J. Chem. Phys. 152, 124119 (2020)
- F. Bonafé, E.I. Albar, S. Ohlmann, V. Kosheleva, C. Bustamante, F. Troisi, H. Appel and A. Rubio. Full minimal coupling Maxwell-TDDFT: an ab initio mean-field QED framework beyond the dipole approximation, submitted (2024)
- E.I. Albar, F. Bonafé, V. Kosheleva, H. Appel and A. Rubio. High harmonic generation with orbital angular momentum beams: beyond-dipole corrections, in preparation (2024)
- F. Bonafé, B. Aradi, B. Hourahine, C. Medrano, F. Hernández, T. Frauenheim, and C.G. Sánchez, JCTC 16 (7), 4454 (2020)
- S. Liu, F. Bonafé, H. Appel, A. Rubio, M. Wolf, and T. Kumagai. ACS Nano 17 (11), 10172 (2023)
