We present an analytical approach to the frequency response of the interacting resonant-tunneling devices (RTD’s) to a small ac signal voltage. Within the wideband assumption for the lead electrons and Hartree approximation for the tunneling effect, we obtain a compact formula for the ac conductance. This has an interesting structure in that the geometry factor of the device is separated out from the interaction in the device. This feature allows us to get some physical insight into the effect of resonance and interaction on the ac response. In particular, we interpret the ac response in the physical picture of photon-assisted resonance between the Fermi surface and the central electron spectrum. The consistency between our result and other approaches is shown for the noninteracting system. We also apply our formula to the ac response of interacting RTD’s, where the Hubbard electron-electron interaction in the resonant region is taken into account, and the remarkable features of charging effects on the ac response are presented. © 1996 The American Physical Society.

• Received 23 January 1996

DOI:https://doi.org/10.1103/PhysRevB.54.10807