AI 中文总结
本研究制备(Cu,C)-1234/YBCO异质结构，发现(Cu,C)-1234薄膜厚度降至18 nm以下发生超导体-绝缘体转变，与YBCO耦合可恢复超导性，厚度过薄时超导性被抑制，为研究高温超导体界面耦合提供新平台。
AI 中文摘要
超导邻近效应及相关的厚度驱动的性质演化是理解高温超导体的重要问题。在邻近系统中，超导体-超导体（S-S'）体系因两种材料均存在本征超导性而具有特殊性，该平台允许不同的超导序在界面处竞争、耦合与重构。本研究制备了在LAO(001)衬底上生长的(Cu,C)-1234/YBCO异质结构，其中底部YBCO层厚度固定为150 nm，顶部(Cu,C)-1234层厚度分别为188 nm、87 nm、18 nm及估算的1.2 nm，同时保留了组分薄膜。电输运表征表明，随着厚度减小，(Cu,C)-1234薄膜性能退化，且在厚度从较厚降至18 nm以下时发生超导体-绝缘体转变（SIT）。相反，当绝缘的(Cu,C)-1234层与超导YBCO耦合时，电输运测量中观测到超导性重新建立；当(Cu,C)-1234厚度进一步减小至约1.2 nm时，恢复的超导性被强烈抑制。观测到的厚度依赖性与以下情景一致：在二维极限下，无序增加和维度限制占主导之前，界面耦合在有限厚度范围内恢复超导性。本工作为研究铜氧化物超导体之间的界面耦合建立了有前景的平台，并为高温超导体异质结构中的超导邻近效应提供了新见解。
英文摘要
Superconducting proximity effect and related thickness-driven property evolution remain an important issue in understanding high temperature superconductors. Among proximity systems, superconductor-superconductor (S-S') is special for the existence of intrinsic superconductivity in both materials. Such platform allows the different superconducting orders to compete, couple and reconstruct at the interface. In this paper, (Cu,C)-1234/YBCO heterostructure grown on LAO (001) with fixed thickness of bottom YBCO layer as 150 nm and varied thickness of top (Cu,C)-1234 layer as 188nm, 87 nm, 18nm and estimated 1.2 nm were fabricated and component films were preserved. Electrical transport characterization indicated that as the thickness decrease the (Cu,C)-1234 film degrades and underwent the superconductor-insulator transition (SIT) from thicker to less than 18 nm. In contrast, superconductivity is re-established in transport measurements when the insulating (Cu,C)-1234 layer is coupled to superconducting YBCO As the (Cu,C)-1234 thickness is further reduced to approximately 1.2 nm, the recovered superconductivity is strongly suppressed. The observed thickness dependence is consistent with a scenario in which interfacial coupling restores superconductivity over a finite thickness range before increasing disorder and dimensional confinement dominate in the two-dimensional limit. This work establishes a promising platform for investigating interfacial coupling between cuprate superconductors and provides new insight into the superconducting proximity effect in high-temperature superconducting heterostructures.
