Equilibrium and Transient Broadband THz Conductivity of Gated Graphene

Graphene's distinctive electronic properties -- linear energy bands, zero-energy bandgap and tunable carrier density -- underscore its versatility. Understanding its responses in equilibrium and photoexcited conditions is key to unlocking its full potential. This research, employing optical pump - terahertz probe spectroscopy, uncovers disparities between charge-neutral and doped graphene responses in equilibrium conditions. A novel model is formulated to elucidate these deviations. Additionally, when selectively photoexcited by near-infrared pulses, graphene displays remarkably extended photodynamic responses attributed to interplaying cooling mechanisms. This work deepens our grasp of graphene's behaviour, which is vital for harnessing its potential, and underscores its relevance in diverse technological realms.