Nonlinear Vortex Dynamics in Superconductors with Anisotropic Pinning Nanostructures

• Applicant: Privatdozent Dr. Oleksandr Dobrovolskiy
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2011 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 200044433

The fabrication of uniaxial or bianisotropic pinning structures in thin films opens up a controlled pathway to govern the mixed-state resistive response of type-II superconductors with a perspective of using it for fluxonics applications, i. e. manipulating single vortices similar to electrons in nano- and microelectronics. Moreover, such films provide a model system with fully predictable properties within a state-of-the-art theoretical approach of describing the nonlinear vortex dynamics under the influence of anisotropic pinning. The deduction of anisotropic pinning potential parameters from resistivity data will allow for the first time to answer the following questions: In which frequency range is a harmonic generation most pronounced? How can one optimize special (bianisotropic and asymmetric-ratchet) nanostructures to provide the most suitable pinning potential characteristics for microwave device fabrication? Is there an interference effect between the Hall- and the ratchet-effect? In order to answer these questions an original rotating-current scheme will be used and special methods for asymmetric signal averaging be applied. The expected results are of interest not only for thin-film superconductors but they will be generic to all similar noise-mediated systems subjected to DC and AC current driving.

• DFG Programme: Research Grants