Imaging of Microscopic Sources of Resistive and Reactive Nonlinearities in Superconducting Microwave Devices

• Published in: IEEE transactions on applied superconductivity 2007-06, Vol.17 (2), p.902-905
• Main Authors: Zhuravel, A.P., Anlage, S.M., Ustinov, A.V.
• Format: Article
• Language: English
• Subjects: AGING MECHANISMS; Applied sciences; Circuit properties; COPPER OXIDE; Devices; Electric, optical and optoelectronic circuits; ELECTRICAL CONDUCTIVITY; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; ELECTRONIC PRODUCTS; Electronics; Exact sciences and technology; High- {\rm T}_{\rm c} superconductors; Intermodulation; laser scanning microscopy; LASERS; Masers; MICROSCOPY; Microwave and submillimeter wave devices, electron transfer devices; microwave devices; Microwave imaging; Microwave theory and techniques; MICROWAVES; Nonlinearity; Oscillators, resonators, synthetizers; Planar transmission lines; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Strips; Superconducting devices; Superconducting microwave devices; Superconducting thin films; Superconducting transmission lines; SUPERCONDUCTIVITY; SUPERCONDUCTORS; THIN FILMS; Two dimensional; YBCO superconductors
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2007.897322

The technique of low-temperature laser scanning microscopy (LSM) has been applied to the investigation of local microwave properties in operating YBa 2 Cu 3 O 7 /LaAlO 3 thin-film resonators patterned into a meandering strip transmission line. By using a modified newly developed procedure of spatially-resolved complex impedance partition, the influence of inhomogeneous current flow on the formation of nonlinear (NL) microwave response in such planar devices is analysed in terms of the independent impact from resistive and inductive components. The modified procedure developed here is dramatically faster than our previous method. The LSM capability to probe the spatial variations of two-tone, third-order intermodulation photoresponse on micron length scales is used to find the 2D distribution of the local sources of microwave NL. The results show that the dominant sources of microwave NL are strongly localized in the resistive domains.