THE NATURE OF SUPERCONDUCTING FLUCTUATIONS AND NEW ASPECTS IN HIGH Tc SUPERCONDUCTORS

Autori

  • Alessandro Lascialfari Dipartimento di Fisica & INSTM, Università degli Studi di Pavia | Dipartimento di Fisica “A. Volta”, Università degli Studi di Pavia
  • Attilio Rigamonti Dipartimento di Fisica “A. Volta”, Università degli Studi di Pavia

DOI:

https://doi.org/10.4081/scie.2017.600

Abstract

After a brief introduction to thermodynamical superconducting fluctuations, some experimental results in different systems are presented. Superconducting fluctuations were predicted and revealed in nanoparticles of conventional superconductors since late 60s. However, just in the last two decades phenomena related to an anomalous diamagnetism have been discovered in high-Tc underdoped compounds, mainly by collecting the isothermal magnetization curves above the critical temperature Tc. These experimental data can be interpreted in terms of fluctuations of the phase of the order parameter and a related theoretical model can explain the results in cuprates, pnictides and Fe-based materials. Such results, here presented together with preliminary data on a Ca-based high-Tc system, allow one to extract a fundamental parameter, the upturn magnetic field above which the diamagnetic magnetization initiates to decrease on increasing the field. Its temperature dependence distinguishes among diamagnetic effects related to superconducting phase fluctuations and to analogous effects due to chemical inhomogenities.

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Pubblicato

2020-03-26

Come citare

Lascialfari, A., & Rigamonti, A. (2020). THE NATURE OF SUPERCONDUCTING FLUCTUATIONS AND NEW ASPECTS IN HIGH Tc SUPERCONDUCTORS. Istituto Lombardo - Accademia Di Scienze E Lettere - Rendiconti Di Scienze. https://doi.org/10.4081/scie.2017.600