ÖPG-CMD Joint Meeting 2026

Role of pulse duration and chirality in high harmonic generation from a chiral Weyl semimetal

Sep 21, 2026, 4:45 PM

15m

HS 15.12 (University of Graz)

3) Contributed talk M03 - Correlated Materials Out of Equilibrium Mini-Colloquium

Speaker

Dr Alba de las Heras (Max Planck Institute for the Structure and Dynamics of Matter (MPSD))

Description

The potential of high harmonic generation (HHG) from chiral topological materials is under investigation. Our time-dependent density-functional theory (TDDFT) calculations in the prototypical chiral Weyl semimetal RhSi show two significant features [1]. On the one hand, a pulse-duration-sensitive cutoff in HHG arises from a progressive promotion of electron population to high conduction bands. The intricate band crossing network of RhSi favours excited ladder electrons, a mechanism that can substantially extend HHG to higher photon energies. Unlike typical scenarios, the strong multi-band coupling establishes the driving pulse duration as a key parameter that has not been exploited in solid-state HHG.

On the other hand, the chiral crystal structure of RhSi enables the synthesis of locally chiral near fields exhibiting an asymmetric instantaneous torsion on attosecond timescales. The concept of locally chiral light constitutes a novel paradigm for efficient enantiomer detection[2], predicting higher chiral sensitivity than circularly polarized or orbital angular momentum beams. Our TDDFT results show that a 3D chiral polarization is naturally imprinted in the attosecond electric field emerging from the chiral Weyl semimetal in the interaction with a circularly polarized driving pulse.

These theoretical findings motivate future experiments to track high-energy band crossings and in-situ attosecond locally chiral light, advancing prospects for compact extreme-ultraviolet sources, enantiomer detection and ultrafast optoelectronics.

[1] A. de las Heras, O. Neufeld & A. Rubio. Pulse-duration-sensitive high harmonics and attosecond locally-chiral light from a chiral topological Weyl semimetal. arXiv preprint: https://doi.org/10.48550/arXiv.2603.05346

[2] D. Ayuso, O. Neufeld, A. F. Ordonez, P. Decleva, G. Lerner, O. Cohen, M. Ivanov & O. Smirnova. Synthetic chiral light for efficient control of chiral light–matter interaction. Nature Photonics, 13(12), 866–871 (2019). https://doi.org/10.1038/s41566-019-0531-2