Bonn 2025 – scientific programme

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A: Fachverband Atomphysik

A 22: Poster – Attosecond Physics

A 22.4: Poster

Wednesday, March 12, 2025, 17:00–19:00, Tent

High harmonic generation in a non-Hermitian Su-Schrieffer-Heeger chain — •Milad Jangjan and Dieter Bauer — Rostock university, Rostock, Germany

Investigating high harmonic generation (HHG) in the One-Dimensional Su-Schrieffer-Heeger (SSH) model with gain and loss is very interesting because it combines nonlinear optical response (HHG) and non-Hermitian physics. We carry out numerical simulations to study how the transmission of energy changes and the gain and loss dynamics affect the band structure, and polarization currents, which are on the very basis of HHG. Our findings show that gain/loss affects the harmonic spectra, the cutoff energies, and some harmonics significantly differ from the response of the Hermitian SSH model. In addition, we identify the trait characteristics of exceptional points in the HHG spectrum, which is a new way to probe non-Hermitian physics through ultrafast nonlinear optics. In this study, we have not only improved our understanding of HHG in non-Hermitian systems but also introduced new ways of making tunable ultrafast light sources and examining topological signatures in materials that are gain/loss-engineered.

Keywords: high harmonic generation; topological phase; SSH model; non-hermitian system