Collective Nature of Orbital Excitations in Layered Cuprates in the Absence of Apical Oxygens
Artikel i vetenskaplig tidskrift, 2024
We have investigated the 3d orbital excitations in CaCuO2 (CCO), Nd2CuO4 (NCO), and La2CuO4 (LCO) using high-resolution resonant inelastic x-ray scattering. In LCO they behave as well-localized excitations, similarly to several other cuprates. On the contrary, in CCO and NCO the dxy orbital clearly disperses, pointing to a collective character of this excitation (orbiton) in compounds without apical oxygen. We ascribe the origin of the dispersion as stemming from a substantial next-nearest-neighbor (NNN) orbital superexchange. Such an exchange leads to the liberation of the orbiton from its coupling to magnons, which is associated with the orbiton hopping between nearest neighbor copper sites. Finally, we show that the exceptionally large NNN orbital superexchange can be traced back to the absence of apical oxygens suppressing the charge transfer energy.
Författare
L. Martinelli
Politecnico di Milano
Universität Zürich
K. Wohlfeld
Uniwersytet Warszawski
Jonathan Pelliciari
Brookhaven National Laboratory
Massachusetts Institute of Technology (MIT)
Riccardo Arpaia
Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik
Nicholas B. Brookes
European Synchrotron Radiation Facility (ESRF)
D. Di Castro
Universita degli Studi di Roma Tor Vergata
Mirian G. Fernandez
Diamond Light Source
Mingu Kang
Massachusetts Institute of Technology (MIT)
Yoshiharu Krockenberger
NTT Basic Research Laboratories
Kurt Kummer
European Synchrotron Radiation Facility (ESRF)
Daniel E. McNally
Paul Scherrer Institut
Eugenio Paris
Paul Scherrer Institut
T. Schmitt
Paul Scherrer Institut
Hideki Yamamoto
NTT Basic Research Laboratories
Andrew C. Walters
Diamond Light Source
Ke Jin Zhou
Diamond Light Source
Lucio Braicovich
European Synchrotron Radiation Facility (ESRF)
Politecnico di Milano
Riccardo Comin
Massachusetts Institute of Technology (MIT)
Marco Moretti Sala
Politecnico di Milano
Thomas P. Devereaux
Stanford Engineering
Stanford University
M. Daghofer
Universität Stuttgart
Giacomo Ghiringhelli
Politecnico di Milano
Physical Review Letters
0031-9007 (ISSN) 1079-7114 (eISSN)
Vol. 132 6 066004Resonant inelastisk röntgenspridning för att studera förändringar i högtemperatursupraledares fasdiagram orsakade av mekanisk påfrestning och inneslutning
Vetenskapsrådet (VR) (2020-04945), 2021-01-01 -- 2024-12-31.
Ämneskategorier
Den kondenserade materiens fysik
DOI
10.1103/PhysRevLett.132.066004
PubMed
38394564