Fractional Spin Excitations in the Infinite-Layer Cuprate CaCuO2
Artikel i vetenskaplig tidskrift, 2022
We use resonant inelastic x-ray scattering (RIXS) to investigate the magnetic dynamics of the infinite-layer cuprate CaCuO2. We find that close to the (1/2,0) point, the single magnon decays into a broad continuum of excitations accounting for about 80% of the total magnetic spectral weight. Polarization-resolved RIXS spectra reveal the overwhelming dominance of the spin-flip (Delta S = 1) character of this continuum with respect to the Delta S = 0 multimagnon contributions. Moreover, its incident-energy dependence is identical to that of the magnon, supporting a common physical origin. We propose that the continuum originates from the decay of the magnon into spinon pairs, and we relate it to the exceptionally high ring exchange J(c) similar to J(1) of CaCuO2. In the infinite-layer cuprates, long-range and multisite hopping integrals are very important, and they amplify the 2D quantum magnetism effects in spite of the 3D antiferromagnetic Neel order.
Författare
Leonardo Martinelli
Politecnico di Milano
Davide Betto
European Synchrotron Radiation Facility (ESRF)
Kurt Kummer
European Synchrotron Radiation Facility (ESRF)
Riccardo Arpaia
Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik
Lucio Braicovich
Politecnico di Milano
European Synchrotron Radiation Facility (ESRF)
Daniele Di Castro
Universita degli Studi di Roma Tor Vergata
Nicholas B. Brookes
European Synchrotron Radiation Facility (ESRF)
Marco Moretti Sala
Politecnico di Milano
Giacomo Ghiringhelli
Politecnico di Milano
Physical Review X
21603308 (eISSN)
Vol. 12 2 021041Resonant 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
Atom- och molekylfysik och optik
Annan fysik
Den kondenserade materiens fysik
DOI
10.1103/PhysRevX.12.021041