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arXiv · 2311.10066

Hund electronic correlation in La$_3$Ni$_2$O$_7$ under high pressure

Zhenfeng Ouyang·Jia-Ming Wang·Jing-Xuan Wang·Rong-Qiang He·Li Huang·Zhong-Yi Lu
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Abstract

By means of density functional theory plus dynamical mean-field theory (DFT+DMFT), we investigate the correlated electronic structures of La$_3$Ni$_2$O$_7$ under high pressure. Our calculations show that La$_3$Ni$_2$O$_7$ is a multi-orbital Hund metal. Both the 3$d_{z^2}$ and 3$d_{x^2 - y^2}$ orbitals of Ni are close to be half filled and contribute the bands across the Fermi level. Band renormalization and orbital selective electronic correlation are observed. Through imaginary-time correlation functions, the discovery of high-spin configuration, spin-frozen phase, and spin-orbital separation shows that the system is in a frozen moment phase at high temperatures above 290 K and is a Fermi liquid at low temperatures, which is further comfirmed by the calculated spin, orbital, and charge susceptibilities under high temperatures. Our study uncovers Hundness in La$_3$Ni$_2$O$_7$ under high pressure.

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Zhenfeng Ouyang, Jia-Ming Wang, Jing-Xuan Wang, Rong-Qiang He, Li Huang, Zhong-Yi Lu. 2023-11-16. Hund electronic correlation in La$_3$Ni$_2$O$_7$ under high pressure. https://doi.org/10.1103/physrevb.109.115114

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