Quantum ferromagnet in the proximity of the tricritical point

TL;DR

This study demonstrates tuning a metallic quantum ferromagnet near its quantum phase transition using accessible conditions, enabling detailed exploration of quantum critical phenomena.

Contribution

It shows how to experimentally access the vicinity of a quantum phase transition in a metallic ferromagnet through pressure and substitution.

Findings

Tuning Ru-doped UCoAl near the tricritical point is feasible.

The transition line can be driven across the quantum critical point.

Accessible conditions enable detailed studies of quantum critical phenomena.

Abstract

Echoes of quantum phase transitions (QPTs) at finite temperatures are theoretically and experimentally challenging and unexplored topics. Particularly in metallic quantum ferromagnets the experimental investigations are hampered by an intricate preparation of sufficiently pure samples and the access to the proper coordinates in parameter space. The present study shows that it is possible to tune a specific system at easily accessible conditions to the vicinity of its quantum phase transition. The physics is demonstrated on Ru-doped UCoAl, driven by pressure or substitution to and across the tricritical point and follows the first-order transition line to the theoretically presumed QPT. These findings open the possibilities for further in-depth studies of classical and quantum critical phenomena at easily reachable conditions.