Evidence of Mott insulator with thermally induced melting behavior in kagome compound Nb3Cl8
The kagome lattice provides a playground to explore novel correlated quantum states due to the presence of flat bands in its electronic structure. The recently discovered layered kagome compound Nb<sub>3</sub>Cl<sub>8</sub> has been proposed as a Mott insulator coming from the half-filled flat band. Here, we have carried out a systematic transport study to uncover evidence of the Mott insulator in Nb<sub>3</sub>Cl<sub>8</sub> thin flakes. A bipolar semiconducting property with Fermi level close to the conduction band has been revealed. We have further probed the chemical potential of Nb<sub>3</sub>Cl<sub>8</sub> by tracing the charge neutrality point of monolayer graphene proximate to Nb<sub>3</sub>Cl<sub>8</sub>. The gap of Nb<sub>3</sub>Cl<sub>8</sub> flakes is ∼1.10 eV at 100 K and shows pronounced temperature dependence, decreasing substantially with increasing temperature to ∼0.63 eV at 300 K. The melting behavior of the gapped state is consistent with the theoretically proposed Mott insulator in Nb<sub>3</sub>Cl<sub>8</sub>. Our work has demonstrated Nb<sub>3</sub>Cl<sub>8</sub> as a promising platform to study strongly correlated physics at relatively high temperature.
Authors
- Wei Jiang (ORCID: https://orcid.org/0000-0001-6167-1156)
- Qiu Yue Yang
- Xiaoxu Zhao (ORCID: https://orcid.org/0000-0001-9746-3770)
- Kaihui Liu (ORCID: https://orcid.org/0000-0002-8781-2495)
- Takashi Taniguchi (ORCID: https://orcid.org/0000-0002-1467-3105)
- Kenji Watanabe (ORCID: https://orcid.org/0000-0003-3701-8119)
- Zaizhe Zhang (ORCID: https://orcid.org/0000-0002-6034-4070)
- Xiaobo Lu (ORCID: https://orcid.org/0000-0003-3149-4755)
- Zihao Huo (ORCID: https://orcid.org/0000-0003-1698-9768)
- Zhijie Ma (ORCID: https://orcid.org/0000-0001-7544-3533)
- Yi Chen (ORCID: https://orcid.org/0000-0001-9611-8393)
- Lingxiao Li (ORCID: https://orcid.org/0000-0001-5571-5968)
- Min Wu (ORCID: https://orcid.org/0000-0001-9581-2084)
- Youguo Shi
- Jingyi Duan
Institutions
- Beijing Institute of Technology (CN)
- Chinese Academy of Sciences (CN)
- Peking University (CN)
- National Institute for Materials Science (JP)
- Beijing Institute of Optoelectronic Technology (CN)
- FZU ‒ Institute of Physics of the Academy of Sciences of the Czech Republic (CZ)
- Collaborative Innovation Center of Quantum Matter (CN)
- Division of Materials Science and Engineering (AU)
- Material Sciences (United States) (US)
- Beijing Academy of Quantum Information Sciences (CN)
- Institute of Physics (CN)
Publication Details
- Journal
- National Science Review
- Published
- 2025-10-28
- DOI
- https://doi.org/10.1093/nsr/nwaf464
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00