Emergence of a Fermi-surface in the current-driven Hidden state of 1T-TaS$_2$

Yuval Nitzav; Roni Gofman; Ilay Mangel; Abigail Dishi; Nitzan Ragoler; Sajilesh K. P.; Yaron Jarach; Alex Louat; Matthew D. Watson; Cephise Cacho; Irena Feldman; Amit Kanigel

arXiv · 2407.05535

Emergence of a Fermi-surface in the current-driven Hidden state of 1T-TaS$_2$

Yuval Nitzav·Roni Gofman·Ilay Mangel·Abigail Dishi·Nitzan Ragoler·Sajilesh K. P.·Yaron Jarach·Alex Louat·Matthew D. Watson·Cephise Cacho·Irena Feldman·Amit Kanigel

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Abstract

The origin of the insulating state in 1T-TaS$_2$ has long been a subject of debate. A short current pulse transforms this insulating state into a metastable metallic phase. Using micro-ARPES, 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 1T-TaS$_2$, characterized by suppressed energy gaps and bands crossing the Fermi level. Furthermore, the metallic and insulating regions display distinct dispersions along the out-of-plane direction. These observations suggest a scenario in which the current pulse breaks the star-of-David dimers characteristic of the insulating phase, implicating these dimers as the likely origin of the insulating behavior in 1T-TaS$_2$.

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Yuval Nitzav, Roni Gofman, Ilay Mangel, Abigail Dishi, Nitzan Ragoler, Sajilesh K. P., Yaron Jarach, Alex Louat, Matthew D. Watson, Cephise Cacho, Irena Feldman, Amit Kanigel. 2024-07-08. Emergence of a Fermi-surface in the current-driven Hidden state of 1T-TaS$_2$. https://arxiv.org/abs/2407.05535

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