The Nernst effect and the boundaries of the Fermi liquid picture

TL;DR

This paper reviews the Nernst effect in metals, clarifying misconceptions about its magnitude in Fermi liquids and showing that the response varies widely, influenced by electron mobility and Fermi energy.

Contribution

It demonstrates that the Nernst response in Fermi liquids is significant and variable, challenging the assumption of negligible response due to Sondheimer cancelation.

Findings

Nernst response amplitude varies over six orders of magnitude in metals.

The response is approximately proportional to electron mobility divided by Fermi energy.

Contrary to common assumptions, Fermi liquids can exhibit substantial Nernst signals.

Abstract

Following the observation of an anomalous Nernst signal in cuprates, the Nernst effect was explored in a variety of metals and superconductors during the past few years. This paper reviews the results obtained during this exploration, focusing on the Nernst response of normal quasi-particles as opposed to the one generated by superconducting vortices or by short-lived Cooper pairs. Contrary to what has been often assumed, the so-called Sondheimer cancelation does not imply a negligible Nernst response in a Fermi liquid. In fact, the amplitude of the Nernst response measured in various metals in the low-temperature limit is scattered over six orders of magnitude. According to the data, this amplitude is roughly set by the ratio of electron mobility to Fermi energy in agreement with the implications of the semi-classical transport theory.