Dynamic electron transport theory for multiprobe mesoscopic structures

Using the linear response theory and random phase approximation, we develop a general dynamic electron transport theory for multiprobe mesoscopic structures in an arbitrarily time-dependent external field. In this case, the responses of the dynamic current, charge and internal potential to the external fields can be determined self-consistently. Without loss of generality, charge (current) conservation and gauge invariance under a potential shift are satisfied. As an example, we employ a quantum wire with a single barrier to discuss the response of the internal potential.