We report the observation of a light-induced subpicosecond phase transition in the antiferromagnetic Dirac semimetal EuAgAs, achieved through ultrafast optical excitation. Using ultrafast optical spectroscopy, we probe the nonequilibrium carrier dynamics, discovering distinct fluence-dependent responses in the antiferromagnetic and paramagnetic states, and revealing a possible magnetic order-driven transition between different topological states. Our results demonstrate that EuAgAs, with its highly tunable magnetic structure, possibly offers a unique platform for exploring topological phase transitions. These results underscore the potential of ultrashort optical pulses as powerful tools for the real-time control of topological phases, opening pathways for advances in spintronics, quantum computing, and energy-efficient information technologies.
@article{arxiv.2411.10756,
title = {Ultrafast photoinduced phase transition in the antiferromagnetic Dirac semimetal EuAgAs},
author = {Hao Liu and Chen Zhang and Qi-Yi Wu and Yahui Jin and Ziming Zhu and Jiao-Jiao Song and Sheng-Tao Cui and Zhe Sun and Honghong Wang and Bo Chen and Jun He and Hai-Yun Liu and Yu-Xia Duan and Peter M. Oppeneer and Jian-Qiao Meng},
journal= {arXiv preprint arXiv:2411.10756},
year = {2025}
}