Thermoelectricity of URu$_{2}$Si$_{2}$: giant Nernst effect in the hidden-order state

TL;DR

This study reveals a giant Nernst effect and significant electronic changes in URu$_{2}$Si$_{2}$ during its hidden-order phase transition, shedding light on its complex electronic state.

Contribution

It provides the first detailed measurement of Nernst and Seebeck effects in URu$_{2}$Si$_{2}$, highlighting the impact of hidden order on thermoelectric properties.

Findings

Giant Nernst signal appears in the ordered state.

Ordering increases entropy per itinerant electron.

Ordering decreases electronic scattering rate.

Abstract

We present a study of Nernst and Seebeck coefficients in the heavy-fermion compound URu$_{2}$Si$_{2}$, which hosts a phase transition of unsettled origin. A giant Nernst signal of unprecedented magnitude was found to emerge in the ordered state. Moreover, our analysis of the Seebeck and Hall data indicates that the ordering leads to a sudden increase in the entropy per itinerant electron and to a drastic decrease in the scattering rate.