First order superconducting transition near a ferromagnetic quantum critical point

TL;DR

This paper reveals that near a ferromagnetic quantum critical point, a system can undergo a first order superconducting transition at higher temperatures, avoiding pair-breaking effects typical of second order transitions.

Contribution

It demonstrates that the superconducting transition near a ferromagnetic quantum critical point can be first order, contrasting with previous findings of second order transitions.

Findings

First order transition occurs near FQCP at higher Tc

Second order transition appears only away from FQCP

System avoids pair-breaking effects by changing transition order

Abstract

We address the issue of how triplet superconductivity emerges in an electronic system near a ferromagnetic quantum critical point (FQCP). Previous studies found that the superconducting transition is of second order, and Tc is strongly reduced near the FQCP due to pair-breaking effects from thermal spin fluctuations. In contrast, we demonstrate that near the FQCP, the system avoids pair-breaking effects by undergoing a first order transition at a much larger Tc. A second order superconducting transition emerges only at some distance from the FQCP.