Overview
- Measurements link shifts in the thorium nucleus’s quadrupole electric field—caused by a shape change between energy states—directly to the fine-structure constant.
- Thorium-containing crystals were produced at TU Wien, with precision laser spectroscopy carried out in Boulder, Colorado.
- The reported method achieves roughly a three-order-of-magnitude improvement in sensitivity over previous approaches to probing alpha.
- The demonstrated setup provides a practical platform for long-term searches for temporal or oscillatory variations in fundamental constants.
- The authors emphasize this is a methodological advance and report no evidence that the fine-structure constant is varying.