Open AccessDimensionality‐Controlled Evolution of Charge‐Transfer Energy in Digital Nickelates Superlattices
Author(s) -
Lu Xiangle,
Liu Jishan,
Zhang Nian,
Xie Binping,
Yang Shuai,
Liu Wanling,
Jiang Zhicheng,
Huang Zhe,
Yang Yichen,
Miao Jin,
Li Wei,
Cho Soohyun,
Liu Zhengtai,
Liu Zhonghao,
Shen Dawei
Publication year - 2022
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202105864
Subject(s) - charge (physics) , superlattice , condensed matter physics , ground state , curse of dimensionality , superconductivity , materials science , electronic structure , spectroscopy , multiplet , chemical physics , physics , spectral line , atomic physics , computer science , astronomy , quantum mechanics , machine learning
Fundamental understanding and control of the electronic structure evolution in rare‐earth nickelates is a fascinating and meaningful issue, as well as being helpful to understand the mechanism of recently discovered superconductivity. Here the dimensionality effect on the ground electronic state in high‐quality (NdNiO 3 ) m /(SrTiO 3 ) 1 superlattices is systematically studied through transport and soft X‐ray absorption spectroscopy. The metal‐to‐insulator transition temperature decreases with the thickness of the NdNiO 3 slab decreasing from bulk to 7 unit cells, then increases gradually as m further reduces to 1 unit cell. Spectral evidence demonstrates that the stabilization of insulating phase can be attributed to the increase of the charge‐transfer energy between O 2p and Ni 3d bands. The prominent multiplet feature on the Ni L 3 edge develops with the decrease of NdNiO 3 slab thickness, suggesting the strengthening of the charge disproportionate state under the dimensional confinement. This work provides convincing evidence that dimensionality is an effective knob to modulate the charge‐transfer energy and thus the collective ground state in nickelates.