Quantum oscillations near the metamagnetic transition in Sr3Ru2O7

TL;DR

This study investigates quantum oscillations in Sr3Ru2O7 near the metamagnetic transition, revealing field-dependent Fermi surface behavior and challenging previous assumptions about quasiparticle mass variations.

Contribution

It provides detailed field-dependent measurements of quantum oscillations in Sr3Ru2O7, clarifying the behavior of quasiparticle masses near the metamagnetic transition.

Findings

Frequencies are strongly field-dependent near the transition

No evidence for strong field dependence of quasiparticle masses

Magnetic breakdown observed in the Fermi surface

Abstract

We report detailed investigation of quantum oscillations in Sr3Ru2O7, observed inductively (the de Haas-van Alphen effect) and thermally (the magnetocaloric effect). Working at fields from 3 T to 18 T allowed us to straddle the metamagnetic transition region and probe the low- and high-field Fermi liquids. The observed frequencies are strongly field-dependent in the vicinity of the metamagnetic transition, and there is evidence for magnetic breakdown. We also present the results of a comprehensive rotation study. The most surprising result concerns the field dependence of the measured quasiparticle masses. Contrary to conclusions previously drawn by some of us as a result of a study performed with a much poorer signal to noise ratio, none of the five Fermi surface branches for which we have good field-dependent data gives evidence for a strong field dependence of the mass. The implications of these experimental findings are discussed.