论文标题
$ s $波超导体中导热率的较弱定位校正
Weak localization corrections to the thermal conductivity in $s$-wave superconductors
论文作者
论文摘要
我们研究了无序$ S $波超导体的导热率。为了扩展正常金属的先前作品，我们开发了一种形式主义，可以解决粒子扩散以及弱定位（WL）和弱反定位（WAL）效应。使用绿色的功能图解技术，该技术通过在Nambu空间中工作来考虑系统的超导性，我们确定了系统的低能模式，Diffuson和Cooperon。表征扩散状态的时间尺度取决于能量。这与正常状态相反，在正常状态下，相关时间尺度是平均空闲时间$τ_e$，独立于能源。能量依赖性引入了一种新颖的能量尺度$ \ VAREPSILON _* $，它在无序的超导体（$τ_eδ\ ll 1 $，$δ$ a GAP）中由$ \ varepsilon_* = \ sqrt {δ/τ_e} $给出。从低能模式的扩散行为中，我们获得了对导热率的WL校正。我们在二维上明确表达。我们确定校正明确依赖于$ \ varepsilon _*$的制度，并提出了一个最佳制度，以在实验中验证我们的结果。
We study the thermal conductivity in disordered $s$-wave superconductors. Expanding on previous works for normal metals, we develop a formalism that tackles particle diffusion as well as the weak localization (WL) and weak anti-localization (WAL) effects. Using a Green's functions diagrammatic technique, which takes into account the superconducting nature of the system by working in Nambu space, we identify the system's low-energy modes, the diffuson and the Cooperon. The time scales that characterize the diffusive regime are energy dependent; this is in contrast with the the normal state, where the relevant time scale is the mean free time $τ_e$, independent of energy. The energy dependence introduces a novel energy scale $\varepsilon_*$, which in disordered superconductors ($τ_e Δ\ll 1$, with $Δ$ the gap) is given by $\varepsilon_* = \sqrt{Δ/τ_e}$. From the diffusive behavior of the low-energy modes, we obtain the WL correction to the thermal conductivity. We give explicitly expressions in two dimensions. We determine the regimes in which the correction depends explicitly on $\varepsilon_*$ and propose an optimal regime to verify our results in an experiment.
