Electron-plasmon interaction induced plasmonic-polaron band replication in epitaxial perovskite SrIrO$_3$ 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

arXiv · 2103.08192

Electron-plasmon interaction induced plasmonic-polaron band replication in epitaxial perovskite SrIrO$_3$ 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

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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 SrIrO$_3$ 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.

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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. 2021-03-15. Electron-plasmon interaction induced plasmonic-polaron band replication in epitaxial perovskite SrIrO$_3$ films. https://doi.org/10.1016/j.scib.2020.10.003

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