Estimation of switching characteristics in quantum-dot cellular automata using probability model

Quantum-dot cellular automata (QCA) is a novel computational paradigm which utilises the quantum mechanism to encode and process bit information. The switching characteristics of the QCA majority gate are evaluated by using the proposed probability model. All kinds of probabilities are achieved by solving the time-independent Schrodinger equation. The simulation results reveal that the majority gate switches at a higher correct probability when the cell distance and the size decrease. Cell miniaturisation would raise a significant implication in how to realise reliable QCA fabrication. In addition, the results also illuminate that majority output has different probabilities when the inputs change. Therefore, to analyse the QCA circuit reliability by using the probability model, all the input combinations must be considered.