Thermoelectric power quantum oscillations in the ferromagnet UGe$_2$

TL;DR

This study investigates quantum oscillations in the thermoelectric power of ferromagnetic UGe$_2$, revealing detailed Fermi-surface information and validating thermoelectric measurements as a powerful tool for electronic structure analysis.

Contribution

It provides the first detailed analysis of quantum oscillations in thermoelectric power in UGe$_2$, comparing experimental results with band-structure calculations and other quantum oscillation techniques.

Findings

Observation of large quantum oscillations in thermoelectric power at low temperatures.

Good agreement between thermoelectric, resistivity, and other quantum oscillation measurements.

Thermoelectric power effectively probes Fermi-surface properties in UGe$_2$.

Abstract

We present thermoelectric power and resistivity measurements in the ferromagnet UGe$_2$ as a function of temperature and magnetic field. At low temperature, huge quantum oscillations are observed in the thermoelectric power as a function of the magnetic field applied along the $a$ axis. The frequencies of the extreme orbits are determined and an analysis of the cyclotron masses is performed following different theoretical approaches for quantum oscillations detected in the thermoelectric power. They are compared to those obtained by Shubnikov-de Haas experiments on the same crystal and previous de Haas-van Alphen experiments. The agreement of the different probes confirms thermoelectric power as an excellent probe to extract simultaneously both microscopic and macroscopic information on the Fermi-surface properties. Band-structure calculations of UGe$_2$ in the ferromagnetic state are compared to the experiment.