论文标题
颗粒超导体中涡流中的巨大电子
Gapful electrons in a vortex core in granular superconductors
论文作者
论文摘要
我们计算颗粒超导体中涡流内部状态（DOS）的准颗粒密度，从而推广适用于脏超导体的经典解决方案。涡流的USADEL方程的离散版本是为广泛参数而数值求解的。当涡旋尺寸$ξ$与相邻谷物$ l $之间的距离相媲美时，电子dos被发现很大。 Minigap幅度$ e_g $从零以$ξ\ $ 1.4 l $生长，到超导差距的第三$ $Δ_0$的第三$ $δ_0$ $ξ\约0.5 l $。缺乏低能激发是了解最近在颗粒状Al混合状态下观察到的微波耗散所需的主要成分。
We calculate the quasiparticle density of states (DoS) inside the vortex core in a granular superconductor, generalizing the classical solution applicable for dirty superconductors. A discrete version of the Usadel equation for a vortex is derived and solved numerically for a broad range of parameters. Electron DoS is found to be gapful when the vortex size $ξ$ becomes comparable to the distance between neighboring grains $l$. Minigap magnitude $E_g$ grows from zero at $ξ\approx 1.4 l$ to third of superconducting gap $Δ_0 $ at $ξ\approx 0.5 l$. The absence of low-energy excitations is the main ingredient needed to understand strong suppression of microwave dissipation recently observed in a mixed state of granular Al.
