The BCS universal ratios such as the gap ratio and superconducting jump of the electronic heat capacity normalized to its normal state value are calculated using a simple single-electron model with equal level spacing. The BCS theory predicts that the size dependence of these ratios can be observed in nm-sized clusters if T_c/ω_D < 0.1, where ω_D is the Debye energy. Under these conditions, the values of these ratios become less than their bulk values in the BCS weak coupling limit. The N-dependence of some analogues of the BCS universal ratios in the canonical formalism is discussed.

中文翻译：

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有限系统中的BCS通用比

的BCS通用比率，如间隙比率和归一化到其正常状态值的电子热容量的超导跳使用以相等的水平间隔的简单的单电子模型计算。的BCS理论预言这些比率的大小依赖性可以在观察到纳米尺度的簇如果Ť _Ç / ω _d  <0.1，其中ω _d是德拜能量。在这些条件下，这些比率的值变得小于BCS弱耦合极限中的体积值。所述Ñ所述的一些类似物的-dependence BCS 讨论了规范形式主义中的普遍比率。