Bi2Sr2CaCu2O8 Intrinsic Josephson junctions as coherent THz emitters

在太赫兹（THz）范围内仍然缺乏良好的有源或无源器件。这种设备将为材料检测或医学诊断的非破坏性成像，或材料和分子的新型光谱研究等应用打开一扇窗。由高温超导体Bi2Sr2CaCu2O8制成的内禀约瑟夫森结堆叠最近被证明在这种状态下工作。本研究的目的是研究本征约瑟夫森结堆的太赫兹辐射。目标有两个：一方面，我们想要理解和模拟太赫兹产生的机制。特别是在产生太赫兹辐射的热点和冷区共存的高偏置区，太赫兹辐射的产生机制尚不清楚。详细的了解将是必要的，以找到限制，例如，最大发射功率和最小线宽，可以实现的单一堆栈或阵列堆栈。第二项任务是在实验场地上优化本征结堆的太赫兹辐射，并提供应用演示（例如在光谱学或太赫兹成像方面）。这两个部分将由H. B. Wang（筑波国家材料科学研究所和南京超导电子研究所）、V. P. Koshelets（莫斯科Kotel’nikov无线电工程和电子研究所）和申请人密切合作完成。

There is still a lack of good active or passive devices operating in the Terahertz (THz) range. Such devices would open a window to applications like non-destructive imaging for materials testing or medical diagnosis, or to novel spectroscopic studies of materials and molecules. Stacks of intrinsic Josephson junctions made of the high temperature superconductor Bi2Sr2CaCu2O8 have recently been shown to operate in this regime. The objective of the present proposal is to investigate THz emission from intrinsic Josephson junction stacks. The goals are twofold: On the one hand we want to understand and model the mechanism of THz generation. Particularly, in the high bias regime where a hot spot and a cold region producing the THz radiation coexist, the mechanism of THz generation is not understood well. A detailed understanding will be necessary to find limits on, e.g., the maximum emission power and the minimum linewidth that can be achieved either for single stacks or for arrays of stacks. The second task is to optimize THz emission from intrinsic junction stacks on experimental grounds and offer demonstrations of applications (e. g. in terms of spectroscopy or THz imaging). Both parts will be performed in close collaboration between the groups of H. B. Wang (National Institute of Material Science, Tsukuba and Research Institute of Superconductor Electronics, Nanjing), V. P. Koshelets (Kotel'nikov Institute of Radio Engineering and Electronics, Moskau) and the applicant.