Experimental studies of superconducting gap structure and quantum fluctuations in novel superconductors and heavy fermion compounds

TL;DR

This paper investigates the superconducting gap structure and quantum fluctuations in novel superconductors and heavy fermion compounds using various experimental techniques to understand their unconventional pairing mechanisms.

Contribution

It provides new experimental insights into the magnetic, transport, and microscopic properties of specific novel and conventional superconductors.

Findings

Identification of superconducting gap structures

Observation of quantum fluctuations effects

Insights into pairing symmetries in novel superconductors

Abstract

Since its discovery more than a century ago, superconductivity has been at the epicentre of condensed matter physics research. The electron phonon coupling in conventional superconductors, which obeys BCS theory, causes an attractive interaction, resulting in a unique isotropic and fixed sign pairing symmetry ground state. Exotic pairing symmetries are hard to come by in this favourable interaction. While unconventional superconductivity is still a mystery, the potential for novel and exotic coupling symmetries due to the interplay of structural symmetries and Fermi surface (FS) topology makes it a fascinating research issue. In this thesis, we have investigated the magnetic, transport, and microscopic properties of the conventional superconductors HfIrSi, ZrIrSi, and novel superconductors ThCoC$_{2}$, CeIr$_{3}$, primarily through the use of a variety of complementary experimental techniques such as low temperature resistivity, magnetization, heat capacity, and muon spin rotation and relaxation measurements.