Observation of Mott instability at the valence transition of f-electron system

Haifeng Yang; Jingjing Gao; Yingying Cao; Yuanji Xu; Aiji Liang; Xiang Xu; Yujie Chen; Shuai Liu; Kui Huang; Lixuan Xu; Chengwei Wang; Shengtao Cui; Meixiao Wang; Lexian Yang; Xuan Luo; Yuping Sun; Yi-Feng Yang; Zhongkai Liu; Yulin Chen

doi:10.1093/nsr/nwad035

Observation of Mott instability at the valence transition of f-electron system

Natl Sci Rev. 2023 Feb 28;10(6):nwad035. doi: 10.1093/nsr/nwad035. eCollection 2023 Jun.

Authors

Haifeng Yang¹, Jingjing Gao^{2

3}, Yingying Cao^{4

5}, Yuanji Xu⁴, Aiji Liang^{1

6}, Xiang Xu⁷, Yujie Chen⁷, Shuai Liu¹, Kui Huang¹, Lixuan Xu⁸, Chengwei Wang⁸, Shengtao Cui¹, Meixiao Wang^{1

6}, Lexian Yang⁷, Xuan Luo², Yuping Sun^{2

9

10}, Yi-Feng Yang^{4

5

11}, Zhongkai Liu^{1

6}, Yulin Chen^{1

6

12}

Affiliations

¹ School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
² Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
³ Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China.
⁴ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
⁵ University of Chinese Academy of Sciences, Beijing 100049, China.
⁶ ShanghaiTech Laboratory for Topological Physics, Shanghai 201210, China.
⁷ State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China.
⁸ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China.
⁹ High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.
¹⁰ Collaborative Innovation Center of Microstructures, Nanjing University, Nanjing 210093, China.
¹¹ Songshan Lake Materials Laboratory, Dongguan 523808, China.
¹² Department of Physics, University of Oxford, Oxford, OX1 3PU, UK.

Abstract

Mott physics plays a critical role in materials with strong electronic correlations. Mott insulator-to-metal transition can be driven by chemical doping, external pressure, temperature and gate voltage, which is often seen in transition metal oxides with 3d electrons near the Fermi energy (e.g. cuprate superconductor). In 4f-electron systems, however, the insulator-to-metal transition is mostly driven by Kondo hybridization and the Mott physics has rarely been explored in experiments. Here, by combining the angle-resolved photoemission spectroscopy and strongly correlated band structure calculations, we show that an unusual Mott instability exists in YbInCu₄ accompanying its mysterious first-order valence transition. This contrasts with the prevalent Kondo picture and demonstrates that YbInCu₄ is a unique platform to explore the Mott physics in Kondo lattice systems. Our work provides important insight for the understanding and manipulation of correlated quantum phenomena in the f-electron system.

Keywords: ARPES; DMFT; Kondo coupling; heavy fermions; orbital-selective Mott transition; strong correlations; valence transition.