AI 中文总结
本研究在宽驱动频率下探究双层石墨烯超导量子干涉器件的超导二极管效应微波响应，发现驱动频率可调控二极管效率对微波功率的响应特性，相关模拟能定性复现实验结果，确立该类器件为研究超导结动态特性的多功能平台。
AI 中文摘要
微波辐照已成为调控约瑟夫森结器件中超导二极管效应（SDE）的极具潜力的手段。此前的实验研究主要聚焦于绝热驱动 regime，在此 regime 下二极管效率随微波功率单调递增，可接近1的理想值。然而，超出该 regime 后，SDE 的微波响应在实验上仍未得到充分探索。本研究在宽驱动频率范围内，探究了基于双层石墨烯的超导量子干涉器件（SQUID）中 SDE 的微波响应。结果表明，提高驱动频率会改变二极管效率对微波功率的响应特性：二极管效率与微波功率的依赖关系从绝热 regime 中随微波功率增大的单调增强，演变为超出该 regime 后的非单调行为，最终在足够高的频率下出现符号反转及振荡特性。研究发现，实验观测到的二极管效率的频率依赖功率响应特性，可通过基于电阻分流结模型的模拟定性复现，该模拟采用了从实验中提取的器件电流-相位关系。这些结果确立了双层石墨烯制成的 SQUID 作为研究超导结器件动态特性的多功能平台。
英文摘要
Microwave irradiation has emerged as a promising means to tune the superconducting diode effect (SDE) in Josephson junction devices. Previous experimental studies have mainly focused on the adiabatic-driving regime, in which the diode efficiency increases monotonically with microwave power and can approach the ideal value of unity. Beyond this regime, however, the microwave response of the SDE remains largely unexplored experimentally. In this work, we investigate the microwave response of the SDE in bilayer-graphene-based superconducting quantum interference devices (SQUIDs) under a broad range of driving frequencies. We show that increasing the driving frequency changes the response characteristics of the diode efficiency to microwave power--the dependence of the diode efficiency evolves from monotonic enhancement with increasing microwave power in the adiabatic regime to non-monotonic behavior beyond this regime, and ultimately to sign-reversal as well oscillatory characteristics at sufficiently high frequencies. We find that these experimentally observed frequency-dependent power response characteristics of the diode efficiency can be qualitatively captured by simulations based on the resistively shunted junction model using the device current-phase relations extracted from the experiments. These results establish SQUIDs made from bilayer graphene as a versatile platform for studying dynamic properties of superconducting junction devices.
