论文标题
HBN封装石墨烯约瑟夫森连接的过度阻尼相扩散
Overdamped Phase Diffusion in hBN Encapsulated Graphene Josephson Junctions
论文作者
论文摘要
我们研究了长弹道连接方案中由封装的石墨烯氮化物异质结构制成的约瑟夫森连接的零偏置行为。对于降至2.7k的温度，相对于切换和翻新电流$ I_C $和$ I_R $，连接处似乎是非滞后的。即使在零偏置电流左右，也观察到一个小的非零电阻，并且按照相扩散机理规定的温度尺度。通过改变石墨烯载体浓度，我们能够确认观察到的相扩散机制遵循过度阻尼约瑟夫森连接的趋势。这与大多数基于石墨烯的连接在高频下被环境所阻滞和缩短。
We investigate the zero-bias behavior of Josephson junctions made of encapsulated graphene boron nitride heterostructures in the long ballistic junction regime. For temperatures down to 2.7K, the junctions appear non-hysteretic with respect to the switching and retrapping currents $I_C$ and $I_R$. A small non-zero resistance is observed even around zero bias current, and scales with temperature as dictated by the phase diffusion mechanism. By varying the graphene carrier concentration we are able to confirm that the observed phase diffusion mechanism follows the trend for an overdamped Josephson junction. This is in contrast with the majority of graphene-based junctions which are underdamped and shorted by the environment at high frequencies.
