Low-Energy Charge-Density Excitations in MgB${}_2$: Striking Interplay between Single-Particle and Collective Behavior for Large Momenta

Y. Q. Cai, P. C. Chow, O. D. Restrepo +12

A sharp feature in the charge-density excitation spectra of single-crystal MgB${}_2$, displaying a remarkable cosine-like, periodic energy dispersion with momentum transfer ($q$) a…