Experimental investigation of potential topological and p-wave superconductors

Superconductivity has played a prominent part in condensed matter physics for more than 100 years, but the understanding of this intriguing phenomenon still remains a theoretical challenge. Almost all current theoretical interpretations consider the key element making up the superconducting condensates to be the very formation of Cooper pairs derived from the microscopic Bardeen-Cooper-Schrieffer (BCS) theory in 1957. In this context, superconductors can be classified as conventional (BCS) or unconventional based on the symmetry of the Cooper pairs. Investigation and understanding of the intrinsic properties of unconventional superconductivity are not only crucial for the realization of novel states of quantum matter but could also pave the way to potential device applications. This PhD work is an experimental study of unconventional superconductivity in the superconducting ferromagnet UCoGe and two candidate topological superconductors Cu_xBi₂Se₃ and YPtBi. The main techniques applied have been transport, magnetic and μSR measurements to shed further light on the intricate superconducting pairing mechanism in these novel materials.