论文标题
接近超薄dyba中的二维超导性
Approaching two-dimensional superconductivity in ultrathin DyBa$_2$Cu$_3$O$_{7-δ}$
论文作者
论文摘要
超级流体密度$ρ_s（t）$的温度依赖性已针对一系列超薄MBE种植的dyba $ _2 $ _2 $ _2 $ _3 $ _3 $ o $ _ {7-δ} $ superConductucting（sc）胶片（SC）胶片，由Sub-Mm Wave Tovermentry与时间域Thz Ellipsompopy和IR Ellipsometry结合在一起。我们发现所有电影10 U.C.厚度显示$ρ_s（t）$相同的通用温度依赖性，它遵循单晶yba $ _2 $ _2 $ _3 $ _3 $ o $ o $ _ {7-δ} $的关键行为特征与$ t $接近$ t_c $。在7 U.C.厚实的胶片，$ρ_s（t）$在接近$ t_c $的情况下急剧下降，正如Berezinskii-Kosterlitz所期望的那样，无与伦比的涡流不连接过渡。我们的分析为明确定义的4 U.C.提供了证据。非SC界面层，在顶部留下准2D SC层。我们建议，该界面层中的SC状态被竞争（可能是费用）的顺序抑制。
The temperature dependence of the superfluid density $ρ_s(T)$ has been measured for a series of ultrathin MBE-grown DyBa$_2$Cu$_3$O$_{7-δ}$ superconducting (SC) films by sub-mm wave interferometry combined with time-domain THz spectroscopy and IR ellipsometry. We find that all films 10 u.c. and thicker show the same universal temperature dependence of $ρ_s(T)$, which follows the critical behavior characteristic of single crystal YBa$_2$Cu$_3$O$_{7-δ}$ as $T$ approaches $T_c$. In 7 u.c. thick films, $ρ_s(T)$ declines steeply upon approaching $T_c$, as expected for the Berezinskii-Kosterlitz-Thouless vortex unbinding transition. Our analysis provides evidence for a sharply defined 4 u.c. non-SC interfacial layer, leaving a quasi-2D SC layer on top. We propose that the SC state in this interfacial layer is suppressed by competing (possibly charge) order.
