Resolving the orbital character of low-energy excitations in Mott insulator with intermediate spin-orbit couplingVise andre og tillknytning
2025 (engelsk)Inngår i: Communications Physics, E-ISSN 2399-3650, Vol. 8, nr 1, artikkel-id 210Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]
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.
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Springer Nature , 2025. Vol. 8, nr 1, artikkel-id 210
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-364014DOI: 10.1038/s42005-025-02104-2ISI: 001492220200001Scopus ID: 2-s2.0-105005590604OAI: oai:DiVA.org:kth-364014DiVA, id: diva2:1962851
Merknad
QC 20250603
2025-06-022025-06-022025-07-03bibliografisk kontrollert