Electron-plasmon interaction induced plasmonic-polaron band replication in epitaxial perovskite SrIrO3 films

Zhengtai Liu; Wanling Liu; Ruixiang Zhou; Songhua Cai; Yekai Song; Qi Yao; Xiangle Lu; Jishan Liu; Zhonghao Liu; Zhen Wang; Yi Zheng; Peng Wang; Zhi Liu; Gang Li; Dawei Shen

doi:10.1016/j.scib.2020.10.003

Electron-plasmon interaction induced plasmonic-polaron band replication in epitaxial perovskite SrIrO₃ films

Sci Bull (Beijing). 2021 Mar 15;66(5):433-440. doi: 10.1016/j.scib.2020.10.003. Epub 2020 Oct 14.

Authors

Zhengtai Liu¹, Wanling Liu², Ruixiang Zhou³, Songhua Cai⁴, Yekai Song², Qi Yao³, Xiangle Lu¹, Jishan Liu¹, Zhonghao Liu¹, Zhen Wang⁵, Yi Zheng⁵, Peng Wang⁴, Zhi Liu⁶, Gang Li⁷, Dawei Shen⁸

Affiliations

¹ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China; School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
³ School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
⁴ Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China; Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
⁵ Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China; Department of Physics, Zhejiang University, Hangzhou 310027, China.
⁶ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China; School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
⁷ School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China. Electronic address: [email protected].
⁸ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: [email protected].

PMID: 36654180
DOI: 10.1016/j.scib.2020.10.003

Abstract

Electron-boson interaction is fundamental to a thorough understanding of various exotic properties emerging in many-body physics. In photoemission spectroscopy, photoelectron emission due to photon absorption would trigger diverse collective excitations in solids, including the emergence of phonons, magnons, electron-hole pairs, and plasmons, which naturally provides a reliable pathway to study electron-boson couplings. While fingerprints of electron-phonon/-magnon interactions in this state-of-the-art technique have been well investigated, much less is known about electron-plasmon coupling, and direct observation of the band renormalization solely due to electron-plasmon interactions is extremely challenging. Here by utilizing integrated oxide molecular-beam epitaxy and angle-resolved photoemission spectroscopy, we discover the long sought-after pure electron-plasmon coupling-induced low-lying plasmonic-polaron replica bands in epitaxial semimetallic SrIrO₃ films, in which the characteristic low carrier concentration and narrow bandwidth combine to provide a unique platform where the electron-plasmon interaction can be investigated kinematically in photoemission spectroscopy. This finding enriches the forms of electron band normalization on collective modes in solids and demonstrates that, to obtain a complete understanding of the quasiparticle dynamics in 5d electron systems, the electron-plasmon interaction should be considered on equal footing with the acknowledged electron-electron interaction and spin-orbit coupling.

Keywords: 5d electron systems; Electron-plasmon interaction; Replica bands; perovskite SrIrO(3).