Multiband Metallic Ground State in Multilayered Nickelates La3Ni2O7 and La4Ni3O10 Probed by 139La-NMR at Ambient Pressure

• DOI: 10.7566/jpsj.93.053702
• Publication Date: 2024-04-22T01:00:37Z
• Authors: Masataka Kakoi; Takashi Oi; Yujiro Ohshita; Mitsuharu Yashima; Kazuhiko Kuroki; Takeru Kato; Hidefumi Takahashi; Shintaro Ishiwata; Yoshinobu Adachi; Naoyuki Hatada; Tetsuya Uda; Hidekazu Mukuda
• Keywords: Superconductivity (cond-mat.supr-con); Condensed Matter - Strongly Correlated Electrons; Strongly Correlated Electrons (cond-mat.str-el); Condensed Matter - Superconductivity; FOS: Physical sciences

We report a 139La-NMR study of polycrystalline samples multi(n)-layered nickelates, La3Ni2O7−δ (n = 2) and La4Ni3O10−δ 3), at ambient pressure. Measurements the nuclear magnetic resonance (NMR) spectra spin relaxation rate (1/T1) indicate emergence density wave order with gap below T* ∼ 150 K for ∼130 La4Ni3O10−δ. The finite value 1/T1 indicates metallic ground states remaining Fermi level (EF) under order. These features are attributed to multiple d electron bands different characteristics. Above T*, gradual decrease in 1/T1T upon cooling implies presence band flat dispersion near EF. From our microscopic probes, we point out that these nickelates 2 3) possess similar electronic despite difference formal valence Ni states, which provides basis understanding novel high-Tc superconductivity high pressures.