论文标题
在SNS Andreev接触的动态电导光谱中minima的幅度
Amplitudes of minima in dynamic conductance spectra of the SNS Andreev contact
论文作者
论文摘要
尽管有几种描述了多种Andreev反射（MAR）效应超导体非正式金属螺旋体（SNS）结的理论方法，但详细阐述了MAR的全面和充分描述的问题，但具有很高的实际描述。 In particular, a broadening parameter $Γ$ is still unaccounted at all, whereas a ballistic condition (the mean free path for inelastic scattering $l$ to the barrier width $d$ ratio) is considered only in the framework of Kümmel, Gunsenheimer, and Nikolsky (KGN), as well as Gunsenheimer-Zaikin approaches, for an isotropic case and完全透明的收缩。但是，$ l/d $比率与动态电导频谱（$ di/dv $）功能的影响仍然被忽略，因此是当前工作的目标之一。我们在扩展KGN方法框架中的数值计算开发了$ l/d $变化，以确定Andreev功能的数量及其在$ DI/DV $频谱中的幅度。我们在扩散的SNS连接点（$ l/d \ rightarrow 1 $）的频谱中抑制了Andreev多余的电流，对当前电压$ i（v）$ - 曲线斜率的急剧变化在低偏置处，只有$ ev =2δ$ bias bias bias bias biias bias biias bias bias bias bias bias bias bias bias bias bias bias bias bias bias bias bias bias bias bias bias the $ di $ di $ di/di coppcect $ di/di coppcect $ di/dim-di-div。此外，我们尝试在高透明性SNS连接（超过$ 85〜 \％$）的实验数据和理论预测之间进行首次比较。结果，我们计算了扩展的KGN方法中Andreev特征幅度和区域的温度依赖性，该方法与我们使用“突破开关”技术获得的实验数据一致。
Despite several theoretical approaches describing multiple Andreev reflections (MAR) effect in superconductor-normal metal-superconductor (SNS) junction are elaborated, the problem of comprehensive and adequate description of MAR is highly actual. In particular, a broadening parameter $Γ$ is still unaccounted at all, whereas a ballistic condition (the mean free path for inelastic scattering $l$ to the barrier width $d$ ratio) is considered only in the framework of Kümmel, Gunsenheimer, and Nikolsky (KGN), as well as Gunsenheimer-Zaikin approaches, for an isotropic case and fully-transparent constriction. Nonetheless, an influence of $l/d$ ratio to the dynamic conductance spectrum ($dI/dV$) features remains disregarded, thus being one of the aims of the current work. Our numerical calculations in the framework of an extended KGN approach develop the $l/d$ variation to determine both the number of the Andreev features and their amplitudes in the $dI/dV$ spectrum. We show, in the spectrum of a diffusive SNS junction ($l/d \rightarrow 1$) a suppression of the Andreev excess current, dramatic change in the current voltage $I(V)$-curve slope at low bias, with only the main harmonic at $eV=2Δ$ bias voltage remains well-distinguished in the $dI/dV$-spectrum. Additionally, we attempt to make a first-ever comparison between experimental data for the high-transparency SNS junctions (more than $ 85~\%$) and theoretical predictions. As a result, we calculate the temperature dependences of amplitudes and areas of Andreev features within the extended KGN approach, which qualitatively agrees with our experimental data obtained using a "break-junction" technique.
