Design aspects of Bi 2 Sr 2 CaCu 2 O 8+δ THz sources: optimization of thermal and radiative properties

Beilstein Journal of Nanotechnology

article

Mikhail M. Krasnov¹  Natalia D. Novikova¹  Roger Cattaneo³  Alexey A. Kalenyuk³  Vladimir M. Krasnov² 

[1] Keldysh Institute of Applied Mathematics of RAS;Moscow Institute of Physics and Technology;Department of Physics, Stockholm University, AlbaNova University Center;Institute of Metal Physics of National Academy of Sciences of Ukraine;Kyiv Academic University

关键词: high-temperature superconductivity;    Josephson junctions;    numericalmodelling;    terahertz sources;   

DOI  :  10.3762/bjnano.12.103

学科分类：环境监测和分析

来源: Beilstein - Institut zur Foerderung der Chemischen Wissenschaften

【 摘 要 】

Impedance matching and heat management are important factors influencing the performance of terahertz sources. In this work weanalyze thermal and radiative properties of such devices based on mesa structures of a layered high-temperature superconductorBi2Sr2CaCu2O8+δ. Two types of devices are considered containing either a conventional large single crystal or a whisker. Weperform numerical simulations for various geometrical configurations and parameters and make a comparison with experimentaldata for the two types of devices. It is demonstrated that the structure and the geometry of both the superconductor and the electrodes play important roles. In crystal-based devices an overlap between the crystal and the electrode leads to appearance of a largeparasitic capacitance, which shunts terahertz emission and prevents impedance matching with open space. The overlap is avoided inwhisker-based devices. Furthermore, the whisker and the electrodes form a turnstile (crossed-dipole) antenna facilitating goodimpedance matching. This leads to more than an order of magnitude enhancement of the radiation power efficiency in whiskerbased, compared to crystal-based, devices. These results are in good agreement with presented experimental data.

【 授权许可】

CC BY