Design aspects of Bi2Sr2CaCu2O8+δ THz sources: optimization of thermal and radiative properties
| Autor: | Vladimir M. Krasnov, M. M. Krasnov, Natalia Dmitrievna Novikova, Roger Cattaneo, Alexey A. Kalenyuk |
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| Rok vydání: | 2021 |
| Předmět: |
Technology
Materials science Josephson junctions Science QC1-999 Impedance matching terahertz sources General Physics and Astronomy TP1-1185 Full Research Paper Crystal Parasitic capacitance Turnstile Condensed Matter::Superconductivity Radiative transfer Nanotechnology General Materials Science Electrical and Electronic Engineering business.industry Chemical technology Physics Condensed Matter - Superconductivity numerical modelling Nanoscience high-temperature superconductivity Optoelectronics Antenna (radio) business Single crystal Order of magnitude Physics - Optics |
| Zdroj: | Beilstein Journal of Nanotechnology Beilstein Journal of Nanotechnology, Vol 12, Iss 1, Pp 1392-1403 (2021) |
| ISSN: | 2190-4286 |
| DOI: | 10.3762/bjnano.12.103 |
| Popis: | Impedance matching and heat management are important factors influencing performance of THz sources. In this work we analyze thermal and radiative properties of such devices based on mesa structures of a layered high-temperature superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. Two types of devices are considered, containing either a conventional large single crystal, or a whisker. We perform numerical simulations for various geometrical configurations and parameters and make a comparison with experimental data for the two types of devices. It is demonstrated that the structure and the geometry of both the superconductor and the electrodes are playing important roles. In crystal-based devices an overlap between the crystal and the electrode leads to appearance of a large parasitic capacitance, which shunts THz emission and prevents impedance matching with open space. The overlap is avoided in whisker-based devices. Furthermore, the whisker and the electrodes form a turnstile (crossed-dipole) antenna facilitating good impedance matching. This leads to more than an order of magnitude enhancement of the radiation power efficiency in whisker-based, compared to crystal-based devices. These results are in good agreement with presented experimental data. Comment: Presented at the 12 International Conference on Intrinsic Josephson Effect and Horizons of Superconducting Spintronics (22-25 Sept. 2021, Chisinau, Moldova) |
| Databáze: | OpenAIRE |
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