The case for quantum materials

Nature Physics has an editorial The Rise of Quantum Materials.
In a refreshing change for the Nature Publishing Group, it is devoid of hype.
The editorial nicely gives the scientific background to the sociological observation:

 As it has become clear that the study of emergent properties is no longer restricted to strongly correlated electron systems, a new, broader description has become necessary. And the term that seems to be gaining currency on departmental websites and research programmes is quantum materials. 

[Indeed, I just got a grant with a title "The bad metallic state in quantum materials"]

My only minor comment is that the editorial does not quite explain why "quantum" is appropriate nomenclature.
I would say that is because on some level they have macroscopic properties [e.g. quantised magnetic flux in superconducting vortices and quantised Hall resistance] that are quantum mechanical in sense that they involve Planck's constant. This is the point I try to bring out in my colloquium on emergent quantum matter.