Unusual metamagnetism in CeIrIn$_5$

TL;DR

This study investigates the high-field metamagnetic transition in CeIrIn$_5$, revealing increased scattering, partial Fermi surface polarization, and non-Fermi-liquid behavior near the critical field, advancing understanding of heavy fermion metamagnetism.

Contribution

It provides detailed experimental insights into the metamagnetic transition in CeIrIn$_5$, highlighting the role of quasiparticle localization and critical fluctuations, which were not previously characterized in this compound.

Findings

Resistivity peaks at the critical field and drops above it.

dHvA frequencies are attenuated but not significantly altered by the transition.

Evidence of increased scattering and non-Fermi-liquid behavior near the critical field.

Abstract

We report a high field investigation (up to 45 T) of the metamagnetic transition in CeIrIn$_5$ with resistivity and de-Haas-van-Alphen (dHvA) effect measurements in the temperature range 0.03-1 K. As the magnetic field is increased the resistivity increases, reaches a maximum at the metamagnetic critical field, and falls precipitously for fields just above the transition, while the amplitude of all measurable dHvA frequencies are significantly attenuated near the metamagnetic critical field. However, the dHvA frequencies and cyclotron masses are not substantially altered by the transition. In the low field state, the resistivity is observed to increase toward low temperatures in a singular fashion, a behavior that is rapidly suppressed above the transition. Instead, in the high field state, the resistivity monotonically increases with temperature with a dependence that is more singular than the iconic Fermi-liquid, temperature-squared, behavior. Both the damping of the dHvA amplitudes and the increased resistivity near the metamagnetic critical field indicate an increased scattering rate for charge carriers consistent with critical fluctuation scattering in proximity to a phase transition. The dHvA amplitudes do not uniformly recover above the critical field, with some hole-like orbits being entirely suppressed at high fields. These changes, taken as a whole, suggest that the metamagnetic transition in CeIrIn$_5$ is associated with the polarization and localization of the heaviest of quasiparticles on the hole-like Fermi surface.