The charge-density-wave Weyl semimetal (TaSe4)2I is a candidate for an axion insulator, however it may be obscured by polaron physics. Here, using ultrafast terahertz photocurrent spectroscopy, the authors realize phase switches from the polaronic state, to the charge density wave phase, and to the Weyl phase.
- Bing Cheng
- Di Cheng
- Jigang Wang
