講演情報
[17p-WL2_101-6]XLD Study of Strain-Tuned Interlayer Coupling in Bilayer Nickelates
Kihyuk Lee1, Seonghyeon Kim2, Bongju Kim1, Kookrin Char2, Deok-Yong Cho3, 〇Minu Kim1 (1.Chung-Ang Univ., 2.Seoul National Univ., 3.Jeonbuk National Univ.)
キーワード：
Epitaxial strain、Orbital polarization、Interlayer coupling
Layered Ruddlesden–Popper nickelates provide a unique platform for exploring correlation-driven electronic phases arising from the interplay of orbital degrees of freedom, interlayer coupling, and lattice distortions. Motivated by recent reports of ambient-pressure superconductivity in bilayer La3Ni2O7 and related compounds, we investigate how epitaxial strain controls electronic anisotropy and interlayer coupling in ultrathin La3Ni2O7 films grown by pulsed laser deposition. High-resolution X-ray diffraction and scanning transmission electron microscopy confirm coherently strained bilayer structures with well-defined NiO6 bilayers. X-ray linear dichroism (XLD) measurements reveal pronounced strain-dependent evolution of orbital polarization, indicating a strain-induced redistribution between in-plane and out-of-plane Ni 3d eg orbitals and a concomitant modification of bilayer electronic coupling. These results establish epitaxial strain as a key tuning parameter for manipulating orbital physics and correlation effects in bilayer nickelates, providing crucial insight into the electronic mechanisms that may enable the stabilization of superconductivity in La3Ni2O7 under ambient conditions.