On the thermal peculiarity of the SC transition, precursor to specific heat's "jump": its relation to the "paramagnetic" effect, precursor to Meissner ejection - both revealed in HTSC material by the super-high sensitive SFCO method

TL;DR

This paper explores the physical connection between the paramagnetic peculiarity and the heat capacity jump in superconductors, proposing a two-type Cooper pair model to better understand the fundamental nature of superconductivity.

Contribution

It introduces a theoretical model with singlet and triplet Cooper pairs to explain the observed thermal effects and their common origin in both low and high-temperature superconductors.

Findings

Paramagnetic peculiarity and heat capacity jump share the same physical roots.

Different temperature behaviors of singlet and triplet pairs are identified.

The study supports the existence of triplet superconductivity in Josephson junctions.

Abstract

We have investigated the correlation between the "paramagnetic" peculiarity of the normal-to-superconductive phase transition - detected first in a LTSC tin, in 1989, and then confirmed in HTSC materials with much more higher resolution (by a sensitive SFCO method) - and the other weakly expressed effect, detected also both in LTSC & HTSC materials before their heat capacity's known "jump". In a low-Tc superconductive tin this thermal effect is detected a half century ago, by Corak, but passed unnoticed so far. We show in this work that, externally similar these 2 fine effects really and truly have the same physical roots. To prove this assumption theoretically, and to reveal the reasons for their common origin, we use here a concept, which admits existence of two types of the Cooper pairs in SC materials - "singlet" and "triplet". As we conclude in this paper, they show completely different, non-traditional temperature behavior upon cooling of SC materials. We believe that this study results (along with the "triplet" superconductivity, proven experimentally in Josephson junctions quite recently, with the ferromagnetic barrier) may obtain key importance for the true understanding of the real nature of the superconductive phenomenon (in whole) and to uncover electron "pairing" mechanisms above the Meissner expel (in particular).