▎ 摘　　要

The instability of electron fluid in the channel of graphene field-effect transistors has provided a powerful theoretical basis for the radiation and detection of THz waves. In this paper, the quantum hydrodynamic model governing the characteristics of two electron gas in channel of graphene field-effect transistors is presented. The instability of THz plasma waves is analyzed in the presence of boundary condition with quantum effects. The results show that the strength of quantum effects will lead to an increase in oscillation frequency and instability increment of THz plasma oscillation in graphene field-effect transistors. These properties could make the nanometer graphene field-effect transistors advantageous for realization of practical terahertz oscillations.