Emergence of a Fermi surface in the current-driven hidden state of
Phys. Rev. B 113, 085104 – Published 3 February, 2026
DOI: https://doi.org/10.1103/kj9t-8mys
Abstract
The origin of the insulating state in has long been a subject of debate. A short current pulse transforms this insulating state into a metastable metallic phase. Using micro–angle-resolved photoemission spectroscopy, we investigate the electronic structure of this phase and uncover spatially dependent modifications caused by the current pulse. In some regions of the sample, a Fermi surface emerges, while others remain gapped. Detailed band structure analysis reveals that the metallic regions exhibit an electronic structure similar to that observed in the high-temperature phase of , characterized by suppressed energy gaps and bands crossing the Fermi level. Furthermore, the metallic and insulating regions display distinct out of plane dispersions, consistent with the current pulse influencing the Star of David dimers that characterize the insulating phase.
