Electric field – velocity relation for strongly coupled Fröhlich polaron in emerging 2D materials

Abstract

In this paper we evaluate the electric field—velocity relation for strong electron—LO phonon coupled 2D materials namely HfS2, HfSe2, ZrS2 and ZrSe2 by applying Thornber—Feynman (TF) formalism applied to the case of the 2D Fröhlich polaron. We demonstrate that the generally-accepted Fermi’s Golden Rule based approach breaks down for these strongly coupled materials. We predict ZrSe2 has highest mobility of 449 cm2/V -s at room temperature followed by HfSe2 with 240 cm2/V -s whereas other materials have below 100 cm2/V -s.