Fractional Spin Excitations in the Infinite-Layer Cuprate CaCuO2

@ARTICLE{Martinelli2022,
	author = {Martinelli, Leonardo and Betto, Davide and Kummer, Kurt and Arpaia, Riccardo and Braicovich, Lucio and Di Castro, Daniele and Brookes, Nicholas B. and Moretti Sala, Marco and Ghiringhelli, Giacomo},
	title = {Fractional Spin Excitations in the Infinite-Layer Cuprate CaCuO2},
	year = {2022},
	journal = {Physical Review X},
	volume = {12},
	number = {2},
	doi = {10.1103/PhysRevX.12.021041},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131349230&doi=10.1103%2fPhysRevX.12.021041&partnerID=40&md5=b631e4eadc5f95f148ade64b2123baf1},
	abstract = {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 (?S=1) character of this continuum with respect to the ?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 Jc~J1 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 Néel order.  © 2022 authors. Published by the American Physical Society.},
	type = {Article},
	publication_stage = {Final},
	source = {Scopus},
	note = {All Open Access, Gold Open Access, Green Open Access}
}