Drastic Reduction of Plasmon Damping in Two-Dimensional Electron Disks

V. M. Muravev, P. A. Gusikhin, A. M. Zarezin, I. V. Andreev, S. I. Gubarev, and I. V. Kukushkin, Phys. Rev. B 99, 241406(R) – Published 26 June 2019.

In this Letter, plasmon damping has been investigated using resonant microwave absorption of twodimensional electrons in disks with different diameters. We have found an unexpected drastic reduction of the plasmon damping in the regime of strong retardation. This finding implies large delocalization of the retarded plasmon field outside the plane of the two-dimensional electron system. A universal relationship between the damping of plasmon polariton waves and the retardation parameter is reported.