Vortex Matter in Superconducting Films with Tunable Anisotropy

• Grant number: 17/24786-4
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2018
• End date: March 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Fabiano Colauto
• Grantee: Fabiano Colauto
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Anisotropic superconductors are considered promising for use in fluxonic devices. Usually, the anisotropy of these materials is intrinsic. However, it is possible to turn an isotropic superconductor into an anisotropic one, by applying an in-plane magnetic field along its plane. Such anisotropy is tunable by varying the magnitude and the direction of the in-plane field. We intend to investigate new possibilities to manipulate flux motion: (i) ultrafast propagation of dendritic avalanches, a highly nonlinear phenomenon governed by non-local electrodynamics; and (ii) smooth penetration of vortices, taking account the dynamic of the Vortex Matter. Superconducting films with the anisotropy tunable by freezing in in-plane magnetic fields will be investigated using magneto-optical imaging technique. As complementary techniques, the magnetometry and the electrical current transport ones will be executed. Several superconducting materials will be investigated, for instance, Nb, NbN, MoSi, and MoGe. These materials can be growth under Si(100) substrate using a sputtering technique under ultra-high vacuum. A local superconducting flux injector will be used to trigger flux penetration. When a current pulse is applied through the injector, the vortices are driven into the sample such as a flux avalanche or a smooth flux-flow. The results will be analyzed according to theoretical model for thermomagnetic avalanche nucleation, assuming that frozen-in vortices generate anisotropy in both critical sheet current and thermal conductance. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LEITE GUSMAO PINHEIRO, LINCOLN BRUM; MOTTA, MAYCON; COLAUTO, FABIAN; JOHANSEN, TOM H.; BELLINGERI, EMILIO; BERNINI, CRISTINA; FERDEGHINI, CARLO; ORTIZ, WILSON A.. Imaging Flux Avalanches in V3Si Superconducting Thin Films. IEEE Transactions on Applied Superconductivity, v. 29, n. 5, AUG 2019. (17/24786-4, 07/08072-0, 18/16193-6)