The interaction of light with correlated Weyl semimetals (WSMs) provides a unique platform for exploring non-equilibrium phases and fundamental properties such as chirality. Here, we investigate the structural chirality of (TaSe4)2I, a correlated WSM, under weak optical pumping using Circular Photogalvanic Effect (CPGE) measurements and Raman spectroscopy. Surprisingly, we find that there is a loss of chirality in (TaSe4)2I above a threshold light intensity. We suggest that the loss of chirality is due to an optically driven phase transition into an achiral structure distinct from the ground state. This structural transformation is supported by fluence-dependent Raman spectra, revealing a new peak at low pump fluences that disappears above the threshold fluence. The loss of chirality even at low optical powers suggests that the system quickly transitions into a non WSM phase, and also highlights the importance of considering light-induced structural interactions in understanding the behavior of correlated systems. These studies showcase that even low excitation powers can be used to control the properties of correlated topological systems, opening up new avenues for low power optical devices.
@article{arxiv.2405.18513,
title = {Strong Chirality Suppression in 1-D correlated Weyl Semimetal (TaSe4)2I},
author = {Utkarsh Khandelwal and Harshvardhan Jog and Shupeng Xu and Yicong Chen and Kejian Qu and Chengxi Zhao and Eugene Mele and Daniel P. Shoemaker and Ritesh Agarwal},
journal= {arXiv preprint arXiv:2405.18513},
year = {2024}
}