Živković Ivica, Soh Jian-Rui, Malanyuk Oleg, Yadav Ravi, Pisani Federico, Tehrani Aria M, Tolj Davor, Pasztorova Jana, Hirai Daigorou, Wei Yuan, Zhang Wenliang, Galdino Carlos, Yu Tianlun, Ishii Kenji, Demuer Albin, Yazyev Oleg V, Schmitt Thorsten, Rønnow Henrik M
Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Department of Materials, ETH Zurich, Zurich, Switzerland.
Nat Commun. 2024 Oct 4;15(1):8587. doi: 10.1038/s41467-024-52935-w.
Exotic quantum phases, arising from a complex interplay of charge, spin, lattice and orbital degrees of freedom, are of immense interest to a wide research community. A well-known example of such an entangled behavior is the Jahn-Teller effect, where the lifting of orbital degeneracy proceeds through lattice distortions. Here we demonstrate that a highly-symmetrical 5d double perovskite BaMgReO, comprising a 3D array of isolated ReO octahedra, represents a rare example of a dynamic Jahn-Teller system in the strong spin-orbit coupling regime. Thermodynamic and resonant inelastic x-ray scattering experiments, supported by quantum chemistry calculations, undoubtedly show that the Jahn-Teller instability leads to a ground-state doublet, resolving a long-standing puzzle in this family of compounds. The dynamic state of ReO octahedra persists down to the lowest temperatures, where a multipolar order sets in, allowing for investigations of the interplay between a dynamic JT effect and strongly correlated electron behavior.
由电荷、自旋、晶格和轨道自由度的复杂相互作用产生的奇异量子相，引起了广泛研究群体的极大兴趣。这种纠缠行为的一个著名例子是 Jahn-Teller 效应，其中轨道简并的解除通过晶格畸变来进行。在此，我们证明了一种高度对称的 5d 双钙钛矿 BaMgReO，它由孤立的 ReO 八面体的三维阵列组成，是强自旋轨道耦合 regime 中动态 Jahn-Teller 系统的一个罕见例子。在量子化学计算的支持下，热力学和共振非弹性 x 射线散射实验无疑表明，Jahn-Teller 不稳定性导致基态双重态，解决了该化合物家族中一个长期存在的难题。ReO 八面体的动态状态一直持续到最低温度，此时会出现多极序，从而可以研究动态 JT 效应与强关联电子行为之间的相互作用。
