Pressure Evolution of the Magnetic Field induced Ferromagnetic Fluctuation through the Pseudo-Metamagnetism of CeRu2Si2

TL;DR

This study investigates how pressure affects the magnetic fluctuations and effective mass in CeRu2Si2, revealing invariance in effective mass change across pseudo-metamagnetic transitions and linking these phenomena to superconductivity.

Contribution

It provides new insights into pressure effects on magnetic fluctuations and effective mass in CeRu2Si2, connecting these to metamagnetic transitions and superconductivity mechanisms.

Findings

Effective mass change is pressure-invariant during pseudo-metamagnetic transition.

Comparison with Ce0.9La0.1Ru2Si2 reveals volume expansion effects.

Links between quasiparticle spin-depairing and superconductivity are discussed.

Abstract

Resistivity measurements performed under pressure in the paramagnetic ground state of CeRu2Si2 are reported. They demonstrate that the relative change of effective mass through the pseudo metamagnetic transition is invariant under pressure. The results are compared with the first order metamagnetic transition due to the antiferromagnetism of Ce0.9La0.1Ru2Si2 which corresponds to the "negative" pressure of CeRu2Si2 by volume expansion. Finally, we describe the link between the spin-depairing of quasiparticles on CeRu2Si2 and that of Cooper pairs on the unconventional heavy fermion superconductor CeCoIn5.