Absence of superconductivity and density-wave transition in ambient-pressure tetragonal La4Ni3O10
Mengzhu Shi, Yikang Li, Yuxing Wang, Di Peng, Shaohua Yang, Houpu Li, Kaibao Fan, Kun Jiang, Jun-Feng He, Qiaoshi Zeng, Dongsheng Song, Binghui Ge, Ziji Xiang, Zhenyu Wang, Jianjun Ying, Tao Wu, Xianhui Chen
Abstract
The recent discovery of superconductivity in La3Ni2O7 and La4Ni3O10 under pressure stimulates intensive research interests. These nickelates crystallize in an orthogonal/monoclinic structure and have a density-wave transition at ambient pressure. The application of pressure triggers a transition to tetragonal structure (I4/mmm), which is believed to be a key prerequisite for the emergence of superconductivity. Here, we report the first tetragonal nickelates La4Ni3O10 microcrystals at ambient pressure. In tetragonal La4Ni3O10, transport measurements find that both density-wave and superconducting transitions are absent up to 160 GPa, indicating a robust tetragonal metallic ground state. Meanwhile, density functional theory calculations reveal a considerable contribution of dz2 orbital to the Fermi surface. The concurrent absence of density-wave state and high-pressure superconductivity in tetragonal La4Ni3O10 suggests that the density-wave state instead of tetragonal structure is crucial for the superconductivity in nickelates under pressure. Our findings impose important constraints on the mechanism of pressure-induced superconductivity in nickelates. Superconductivity was recently discovered in La4Ni3O10 under pressure in proximity to a density-wave phase. Here, by stabilizing a tetragonal form of La4Ni3O10 at ambient pressure, the authors show that the density-wave state is crucial for the superconductivity, but the tetragonal structure is not.