论文标题
SN连接中状态密度的特点
Peculiarities of the density of states in SN junctions
论文作者
论文摘要
我们研究了由散装超导体（S）与正常金属（N）膜中的状态密度（DOS）$ν（e）$。我们假设系统是扩散的，而SN接口是透明的。在薄n层的极限（与相干长度相比）中，我们在分析上找到了三种不同类型的DOS特征性，其能量等于散装超导顺序参数$Δ_0$。 （i）在没有逆接近效应的情况下，只要n层的厚度小于临界值，尤其性具有$ν（δ_0）= 0 $的检查标记形式。 （ii）当逆接近效应发挥作用时，检查标记会立即升高，以便$ν（δ_0）> 0 $。 （iii）在进一步增加逆接近效应后，$ν（e）$逐渐演变为垂直特征性（在$ e =δ_0$的无限衍生拐点处）。该交叉由材料匹配参数控制，该参数取决于S和N材料中无序的相对程度。
We study the density of states (DoS) $ν(E)$ in a normal-metallic (N) film contacted by a bulk superconductor (S). We assume that the system is diffusive and the SN interface is transparent. In the limit of thin N layer (compared to the coherence length), we analytically find three different types of the DoS peculiarity at energy equal to the bulk superconducting order parameter $Δ_0$. (i) In the absence of the inverse proximity effect, the peculiarity has the check-mark form with $ν(Δ_0)=0$ as long as the thickness of the N layer is smaller than a critical value. (ii) When the inverse proximity effect comes into play, the check-mark is immediately elevated so that $ν(Δ_0)>0$. (iii) Upon further increasing of the inverse proximity effect, $ν(E)$ gradually evolves to the vertical peculiarity (with an infinite-derivative inflection point at $E=Δ_0$). This crossover is controlled by a materials-matching parameter which depends on the relative degree of disorder in the S and N materials.
