Quantum ferromagnet in the proximity of the tricritical point

Abstract

Quantum phase transitions: Tuned in metallic ferromagnets Clean ferromagnetic systems are predicted to exhibit quantum phase transitions (QPTs) rather than critical points. QPTs happen at zero temperature due to quantum fluctuations between the phases, and can be triggered by non-thermal perturbations such as hydrostatic pressure, chemical composition or magnetic fields. Jan Prokleška at Czesh Charles University and colleagues from Czech Republic and Germany demonstrate that it is possible to tune the QPT of the metallic ferromagnet UCo1-xRuxAl by pressure or weak Ru doping. The experimental study of QPTs in metallic ferromagnets is typically hindered by the extreme conditions required to drive the system into the transition, or by the presence of additional phases such as superconductivity. Instead, UCo1-xRuxAl allows to get access to the QPT at easily accessible experimental conditions, opening the possibility of studying in detail quantum critical phenomena.