AI 中文总结
该研究实现了铝邻近诱导的双层石墨烯量子点接触，揭示其一维输运模式调控混合系统平衡邻近效应与非平衡动力学的规律，为相关超导量子器件研究提供了实验基础。
AI 中文摘要
我们报告了在单层铝超导电极邻近作用下，门控定义的双层石墨烯量子点接触（QPC）的实现。弹道沟道中诱导的超导关联使电导平台提升至超过其正常态的值。此外，我们观测到显著的能隙以上电导异常，这是超导性丧失及安德烈夫超额电流相关崩溃的光谱学特征。通过重构非线性电流-电压特性，我们发现随着QPC连续模式被填充，超额电流的大小会增加。此外，我们发现与超导性丧失相关的开关电流遵循QPC的基础模式结构，呈现出与热耗散驱动转变一致的离散能级。这些结果表明，QPC的一维输运模式同时控制着混合系统的平衡邻近效应与非平衡动力学。
英文摘要
We report the realization of a gate-defined quantum point contact (QPC) in bilayer graphene proximitized by a single aluminum superconducting electrode. Superconducting correlations induced in the ballistic channel enhance the conductance plateaus beyond their normal-state values. In addition, we observe a pronounced above-gap conductance anomaly which serves as a spectroscopic signature of the loss of superconductivity and the associated collapse of the Andreev excess current. By reconstructing the nonlinear current-voltage characteristics, we find that the magnitude of the excess current increases as successive QPC modes are populated. Additionally, we find that the switching current associated with the loss of superconductivity follows the underlying mode structure of the QPC, exhibiting discrete levels consistent with a heat dissipation-driven transition. These results demonstrate that the one-dimensional transport modes of the QPC govern both the equilibrium proximity effect and the non-equilibrium dynamics of the hybrid system.
