Small-signal equivalent circuit for double quantum dots at low-frequencies

Understand

Due to the quantum nature of current flow in single-electron devices, new physical phenomena can manifest when probed at finite frequencies.

• Here, we present a semi-classical small-signal model approach to replace complex single-electron devices by linear parametric circuit components that could be readily used in analogue circuit simulators.
• Our approach is based on weakly-driven quantum two-level systems and here we use it to calculate the finite-frequency impedance of a single-electron double quantum dot (DQD).
• We find that the total impedance is composed by three elements that were previously considered separately: a dissipative term, corresponding to the Sisyphus resistance, and two dispersive terms, comprised of the quantum and tunneling capacitance.