Intrinsic inductive characteristics of resonant tunneling

We have studied the current I(ω,t)=${\mathit{I}}_0$(ω)+${\mathit{I}}_1$(ω,t) through a double-barrier resonant tunneling system (DBRTS) under a dc-ac bias. With a 2D emitter, the ac shift of the resonant level can be determined from ${\mathit{I}}_0$(ω), and the intrinsic inductance of a DBRTS is unambiguously defined from ${\mathit{I}}_1$(ω,t). For presently available DBRT diodes under maximum operation frequency, the photon replica cannot be observed in the I-V curve. With a 3D emitter, a quantum-equivalent-circuit model can be constructed to calculate the maximum operation frequency of the diode, with good agreement with the measured value.