  Adiabatic quantum-flux-parametron (AQFP) logic is an energy-efficient
superconductor logic. It operates with zero static power dissipation and very
low dynamic power dissipation owing to adiabatic switching. In previous
numerical studies, we have evaluated the energy dissipation of basic AQFP logic
gates and demonstrated sub-kBT switching energy, where kB is the Boltzmann's
constant and T is the temperature, by integrating the product of the excitation
current and voltage associated with the gates over time. However, this method
is not applicable to complex logic gates, especially those in which the number
of inputs is different from the number of outputs. In the present study, we
establish a systematic method to evaluate the energy dissipation of general
AQFP logic gates. In the proposed method, the energy dissipation is calculated
by subtracting the energy dissipation of the peripheral circuits from that of
the entire circuit. In this way, the energy change due to the interaction
between gates, which makes it difficult to evaluate the energy dissipation, can
be deducted. We evaluate the energy dissipation of a majority gate using this
method.
