Fermi Surface Reconstruction inside the Hidden Order Phase of URu2Si2 Probed by Thermoelectric Measurements

TL;DR

This study uses thermoelectric measurements to reveal multiple Fermi surface reconstructions within the hidden order phase of URu2Si2 at high magnetic fields, indicating complex electronic phase transitions.

Contribution

It provides the first detailed thermoelectric evidence of successive Fermi surface reconstructions inside the hidden order phase of URu2Si2 at high magnetic fields.

Findings

Successive anomalies in thermoelectric power and Nernst signal at specific fields.

Changes in Shubnikov-de Haas frequencies and effective masses.

Multiple electronic phase transitions within the hidden order phase.

Abstract

We report thermoelectric measurements of the low carrier heavy fermion compound URu2Si2 at high fields up to 34T and at low temperatures down to 500mK. The field dependence of the thermoelectric power (TEP) and the Nernst signal shows successive anomalies deep inside the hidden order (HO) phase. The field position of these anomalies correspond to different changes in the Shubnikov-de Haas frequencies and effective masses around 12 T, 17 T, 23 T and 30 T. These results indicate successive reconstructions of the Fermi surface, which imply electronic phase transitions well within the HO phase.