First-principles study on spin density wave in La$_3$Ni$_2$O$_{7-\delta}$

• DOI: 10.48550/arxiv.2407.19213
• Publication Date: 2024-07-27
• Authors: Xiao-Sheng Ni; Yuyang Ji; Lixin He; Tao Xie; Dao‐Xin Yao; Meng Wang; Kun Cao
• Keywords: Superconductivity (cond-mat.supr-con); Condensed Matter - Materials Science; Condensed Matter - Superconductivity; TA401-492; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; Atomic physics. Constitution and properties of matter; Materials of engineering and construction. Mechanics of materials; QC170-197

The recent discovery of high-temperature superconductivity in high-pressurized La$_3$Ni$_2$O$_{7-\delta}$ has garnered significant attention. Using density functional theory, we investigate the magnetic properties La$_3$Ni$_2$O$_7$ at ambient pressure. Our calculations suggest that with $\delta=0$, double spin stripe phase is favored as ground state. Oxygen vacancies may effectively turn nearest Ni spins into charge sites. Consequently, moderate $\delta$ values, our theoretical state exhibits characteristics both and spin-charge configurations, providing a natural explanation to reconcile seemingly contradictory experimental findings configurations candidates for spin-density-wave phase. With higher anticipate become spin-glass-like noncollinear only short-range order. oxygen are expected significantly impact excitations transition temperatures $T_{SDW}$. We further offer plausible observations measured $T_{SDW}$ appears insensitive variation samples lack direct evidence long-range ordering.