Electronic Band Structure of a Superconducting Nickelate Probed by the Seebeck Coefficient in the Disordered Limit

作者：G. Grissonnanche, Grace A. Pan, Harrison LaBollita, D. Ferenc Segedin, Qi Song, Hanjong Paik, Charles M. Brooks, E. Beauchesne-Blanchet, J.L. González, Antía S. Botana, Julia A. Mundy, B. J. Ramshaw · 发表于：Physical Review X · 年份：2024 · DOI：10.1103/physrevx.14.041021 · 被引用次数：10 · 研究领域：Physics of Superconductivity and Magnetism、Iron-based superconductors research、Superconductivity in MgB2 and Alloys

Superconducting nickelates are a new family of strongly correlated electron materials with a phase diagram closely resembling that of superconducting cuprates. While analogy with the cuprates is natural, very little is known about the metallic state of the nickelates, making these comparisons difficult. We probe the electronic dispersion of thin-film superconducting five-layer ( n = 5 ) and metallic three-layer ( n = 3 ) nickelates by measuring the Seebeck coefficient S . We find a temperature-independent and negative S / T for both n = 5 and n = 3 nickelates. These results are in stark contrast to the strongly temperature-dependent S / T measured at similar electron filling in the cuprate La 1.36 Nd 0.4 Sr 0.24 CuO 4 . The electronic structure calculated from density-functional theory can reproduce the temperature dependence, sign, and amplitude of S / T in the nickelates using Boltzmann transport theory. This demonstrates that the electronic structure obtained from first-principles calculations provides a reliable description of the fermiology of superconducting nickelates and suggests that, despite indications of strong electronic correlations, there are well-defined quasiparticles in the metallic state. Finally, we explain the differences in the Seebeck coefficient between nickelates and cuprates as originating in ...