▎ 摘　　要

This work presents a new substrate platform, which provides tunability of the group velocity and spontaneous emission of a dipolar scatterer graphene-ferroelectric slab hybrid system in the terahertz ranges. We use analytical models to determine the hybridization of graphene surface plasmon and ferroelectric LiNbO3 type I and type II reststrahlen hyperbolic phonon-polariton. The variation of the chemical potential of graphene and the thickness of the ferroelectric layer results in several distinct features. Flipping the group velocity, strongly coupled hybrid hyperbolic surface plasmon-polaritons, and surface plasmon-polariton mode exists for the same momentum at different frequencies. The group velocity sign reversal for both a single-graphene- and double-graphene-integrated system depends on the thickness of the hyperbolic layer and the chemical potential of graphene. Comparative analysis of Purcell radiation is presented for a quantum emitter positioned at different locations between ferroelectric and graphene-integrated ferroelectric layers, revealing that this system can support strong spontaneous emission that can be modulated with the graphene chemical potential. Changing the chemical potential through selective voltage biasing demonstrates a substantial increase or decrease in the decay rate for spontaneous emission. Further analysis of the emission phenomenon shows a dependence on factors, such as the relative radiating source position and the thickness of the ferroelectric film. These characteristics make graphene-ferroelectric materials promising candidates to modify the light-matter interaction at the low terahertz ranges.