基于概率模型的择多逻辑门背景电荷分析

Analysis of the Stray Charge on the Majority Using the Probabilistic Model

建立了时不变双量子阱系统状态转换的概率模型,量化分析了背景电荷对量子元胞自动机(QCA)择多逻辑门的影响。仿真结果表明,决策元胞处于各态概率既受背景电荷位置的影响,还与择多逻辑门的输入密切相关。背景电荷在一定坐标范围内会引起择多逻辑门决策元胞的错误翻转,甚至使决策元胞以接近100%的概率处于非预期态。不同输入状态在相同位置的背景电荷的影响下,决策元胞处在各态的概率并不相同。背景电荷影响下,决策元胞有可能以接近100%的概率处于"X0"或"X1"态,双稳态模型在背景电荷分析中并不适用。此外对比发现,QCA概率模型在背景电荷分析上计算量最小,具有一定的优越性。

A new time-independent state switching probabilistic model of the double-dot system was developed, and the influence of the stray charge on the majority of the quantum-dot cellular automata （QCA） was quantitatively analyzed. The simulation results reveal that the probabilities of the voter cell being at each state are determined by the joint effect of the stray charge location and majority inputs. The stray charge located in a certain scope of the coordinate results in the wrong flip for the voter cell of the majority, and even the approximate 100% probability of the voter cell at unexpected states. With the inputs changing, the affections of the stray charges at the same location on the state of the voter cell differ from each other. Effected by the stray charge, the voter cell may stay at ＂X0＂ or ＂X1 ＂ with the approximate 100% probability. There- fore, the bistable saturation is no longer applicable for the analysis of the stray charge. In addition, the probabilistie model has the superiority in the minimum amount of calculation compared with the previous stray charge analysis methods, such as the intercellular Hartree approximation （ICHA） and full-basis calculation.