Resolving the orbital character of low-energy excitations in Mott insulator with intermediate spin-orbit coupling
Artikel i vetenskaplig tidskrift, 2025
Multi-band Mott insulators with moderate spin-orbit and Hund’s coupling are key reference points for theoretical concept developments of correlated electron systems. The ruthenate Mott insulator Ca2RuO4 has therefore been intensively studied by spectroscopic probes. However, it has been challenging to resolve the fundamental excitations emerging from the hierarchy of electronic energy scales. Here we apply high resolution resonant inelastic x-ray scattering to probe deeper into the low-energy electronic excitations found in Ca2RuO4. In this fashion, we probe a series of spin-orbital excitations. By taking advantage of enhanced energy resolution, we probe a 40 meV mode through the oxygen K-edge. The polarization dependence of this low-energy excitations exposes a distinct orbital nature, originating from the interplay of spin-orbit coupling and octahedral rotations. Additionally, we discuss the role of magnetic correlations to describe the occurrence of excitations with amplitudes which are multiple of a given energy. Such direct determination of relevant electronic energy scales sharpens the target for theory developments of Mott insulators’ orbital degree of freedom.
Författare
Karin von Arx
Chalmers, Fysik, Materialfysik
Universität Zürich
Pascal Rothenbühler
Universität Zürich
Q. Wang
Chinese University of Hong Kong
Universität Zürich
L. Martinelli
Universität Zürich
Jaewon Choi
Diamond Light Source
M. Garcia-Fernandez
Diamond Light Source
S. Agrestini
Diamond Light Source
Ke Jin Zhou
Diamond Light Source
A. Vecchione
Universita degli Studi di Salerno
Consiglio Nazionale delle Ricerche (CNR)
R. Fittipaldi
Universita degli Studi di Salerno
Consiglio Nazionale delle Ricerche (CNR)
Yasmine Sassa
Chalmers, Fysik, Materialfysik
Kungliga Tekniska Högskolan (KTH)
M. Cuoco
Universita degli Studi di Salerno
Consiglio Nazionale delle Ricerche (CNR)
Filomena Forte
Consiglio Nazionale delle Ricerche (CNR)
Universita degli Studi di Salerno
J. Chang
Universität Zürich
Communications Physics
23993650 (eISSN)
Vol. 8 1 210Framtidens Lågdimensionella Skyrmion Material
Vetenskapsrådet (VR) (2017-05078), 2019-06-01 -- 2021-12-31.
Gate Tuneable Superconducting Quantum Electronics (SuperGate)
Europeiska kommissionen (EU) (EC/H2020/964398), 2021-03-01 -- 2024-08-31.
Ämneskategorier (SSIF 2025)
Atom- och molekylfysik och optik
Den kondenserade materiens fysik
Styrkeområden
Materialvetenskap
DOI
10.1038/s42005-025-02104-2
Relaterade dataset
Dataset for publication "Resolving the Orbital Character of Low-energy Excitations in Mott Insulator with Intermediate Spin-orbit Coupling" [dataset]
URI: https://doi.org/10.5281/zenodo.11395839