Universal magnetic excitations in the cuprates

I heard a nice talk by Bernhard Keimer which included a discussion of recent RIXS [Resonant Inelastic X-ray Scattering] results on the cuprates. The relevant Nature Physics article  states
As a major result, we demonstrate the existence of spin-wave-like dispersive magnetic excitations (paramagnons) deep inside the electron–hole spin-flip continuum (up to ~300 meV), for all the investigated doping levels, with spectral weights comparable to those of magnons in the undoped parent compounds.
The work is nicely put in context in a News and Views article by Matthias Vojta.

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