@article{hayashida_magnetic_2025,

title = {Magnetic ground state of the dimer-based hexagonal perovskite Ba_{3}ZnRu_{2}O_{9}},

author = {S. Hayashida and H. Gretarsson and P. Puphal and M. Isobe and E. Goering and Y. Matsumoto and J. Nuss and H. Takagi and M. Hepting and B. Keimer},

url = {https://link.aps.org/doi/10.1103/PhysRevB.111.104418},

doi = {10.1103/PhysRevB.111.104418},

year  = {2025},

date = {2025-03-13},

urldate = {2025-03-01},

journal = {Phys. Rev. B},

volume = {111},

number = {10},

pages = {104418},

abstract = {We investigate the magnetic ground state of single crystals of the ruthenium-dimer-based hexagonal perovskite Ba3⁢ZnRu2⁢O9 using magnetic susceptibility and resonant inelastic x-ray scattering (RIXS) measurements. While a previous study on powder samples exhibited intriguing magnetic behavior, questions about whether the spin state within a Ru2⁢O9 dimer is a conventional 𝑆=3/2 dimer or an orbital-selective 𝑆=1 dimer were raised. The RIXS spectra reveal magnetic excitations from Hund's intraionic multiplet and intradimer spin-triplet transitions. The observed transition energies of the Hund's intraionic multiplets align with the 𝑆=3/2 ground state, contrasting with the theoretically proposed orbital-selective 𝑆=1 dimer state. High-temperature magnetic susceptibility analysis confirms the realization of the spin 𝑆=3/2 dimer state, and the extracted intradimer coupling is consistent with the spin-triplet transition energy observed in the RIXS spectra. These results highlights the ability of “spectroscopic fingerprinting” by RIXS to determine the magnetic ground states of complex materials.},

keywords = {B2},

pubstate = {published},

tppubtype = {article}

}

@article{radhakrishnan_imprinted_2024,

title = {Imprinted atomic displacements drive spin–orbital order in a vanadate perovskite},

author = {P. Radhakrishnan and K. S. Rabinovich and A. V. Boris and K. Fürsich and M. Minola and G. Christiani and G. Logvenov and B. Keimer and E. Benckiser},

url = {https://doi.org/10.1038/s41567-024-02686-8},

doi = {10.1038/s41567-024-02686-8},

year  = {2024},

date = {2024-10-29},

urldate = {2024-10-01},

journal = {Nat. Phys.},

volume = {21},

number = {1},

pages = {126},

abstract = {Perovskites with the generic composition ABO3 exhibit an enormous variety of quantum states, such as orbital order, magnetism and superconductivity. Their flexible and comparatively simple structure allows for straightforward chemical substitution and cube-on-cube combination of different compounds in atomically sharp epitaxial heterostructures. Many of the diverse physical properties of perovskites are determined by small deviations from the ideal cubic perovskite structure, which are challenging to control. Here we show that directional imprinting of atomic displacements in the antiferromagnetic Mott insulator YVO3 can be achieved by depositing epitaxial films on different facets of the same isostructural substrate. These facets were chosen such that other well-known control parameters, including lattice and polarity mismatch with the overlayer, remain nearly unchanged. We observe signatures of staggered orbital and magnetic order and demonstrate distinct spin–orbital ordering patterns on different facets. We attribute these results to the influence of specific octahedral rotation and cation displacement patterns, which are imprinted by the substrate facet, on the covalency of the bonds and the superexchange interactions in YVO3. Our results show that substrate-induced templating of lattice distortion patterns constitutes a pathway for materials design beyond established strain-engineering strategies.},

keywords = {B2},

pubstate = {published},

tppubtype = {article}

}

@article{wang_spin-orbit_2024,

title = {Spin-Orbit Excitons in a Correlated Metal: Raman Scattering Study of Sr_{2}RhO_{4}},

author = {L. Wang and H. Liu and V. Zimmermann and A. K. Yogi and M. Isobe and M. Minola and M. Hepting and G. Khaliullin and B. Keimer},

doi = {10.1103/PhysRevLett.132.116502},

year  = {2024},

date = {2024-03-01},

urldate = {2024-03-01},

journal = {Phys. Rev. Lett.},

volume = {132},

number = {11},

pages = {116502},

abstract = {Using Raman spectroscopy to study the correlated 4d-electron metal Sr2RhO4, we observe pronounced excitations at 220 meV and 240 meV with A1g and B1g symmetries, respectively. We identify them as transitions between the spin-orbit multiplets of the Rh ions, in close analogy to the spin-orbit excitons in the Mott insulators Sr2IrO4 and α−RuCl3. This observation provides direct evidence for the unquenched spin-orbit coupling in Sr2RhO4. A quantitative analysis of the data reveals that the tetragonal crystal field Δ in Sr2RhO4 has a sign opposite to that in insulating Sr2IrO4, which enhances the planar xy orbital character of the effective J=1/2 wave function. This supports a metallic ground state, and suggests that c-axis compression of Sr2RhO4 may transform it into a quasi-two-dimensional antiferromagnetic insulator.},

keywords = {B2},

pubstate = {published},

tppubtype = {article}

}