Exploring AC Transport Properties in the Vicinity of the Superconducting Critical Temperature TC

• Grant number: 24/01816-9
• Support Opportunities: Scholarships abroad - Research
• Start date: July 20, 2024
• End date: July 19, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Renato de Figueiredo Jardim
• Grantee: Renato de Figueiredo Jardim
• Host Investigator: M Brian Maple
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of California, San Diego (UC San Diego), United States
• Associated research grant: 13/07296-2 - CDMF - Center for the Development of Functional Materials, AP.CEPID

Abstract

A Fellowship Grant (BPE) is requested for the development of the scientific research project entitled "Exploring AC Transport Properties in the Vicinity of the Superconducting Critical Temperature TC". It deals with a systematic study of the AC voltage components in phase (real component), out of phase or quadrature (imaginary component) and the higher harmonics when a low frequency AC excitation current w, w < 2 kHz, is applied to several specimens of superconducting materials of types I and II in the form of polycrystalline and thin films samples. The project aims to collect data and subsequent analysis of these contributions in the vicinity of TC, where two phenomena of interest will be investigated: (i) the peak effect in type II superconductors, which corresponds to an anomalous increase of the superconducting critical current density JC in the vicinity of the critical temperature TC and the upper critical thermodynamic field HC2; and (ii) the signatures of the imaginary components in the resistive transition temperature TC in both type I and II superconductors arising from the AC current excitation applied, in analogy with those widely used in AC magnetic susceptibility characterizations. The project ends with an improved understanding of the technique used and its contributions to a deeper comprehension of the two phenomena mentioned above.