Comment on "Signatures of Surface States in Bismuth at High Magnetic Fields"

TL;DR

This paper critically examines recent claims that surface states in bismuth cause high-field Nernst effect anomalies, emphasizing the need for further investigation into their origin beyond current surface state hypotheses.

Contribution

It provides a critical analysis of the proposed surface state explanation for high-field Nernst anomalies in bismuth, challenging recent interpretations.

Findings

Surface states alone may not explain high-field Nernst anomalies.

Further research is needed to identify the true origin of these anomalies.

The proposed surface state hypothesis requires more rigorous testing.

Abstract

Nernst effect is the transverse electric field due to a longitudinal thermal gradient in presence of magnetic field. Its magnitude was recently studied up to 33 T in a bismuth single crystal with a magnetic field oriented along the trigonal axis . In addition to quantum oscillations of the Nernst response, a rich structure with several additional peaks was also detected when the magnetic field exceeded the quantum limit, which is of the order of 10 T in this configuration. The origin of these high-field Nernst anomalies is a subject of ongoing research. Very recently, Seradjeh, Wu, and Phillips have suggested that a surface state can give rise to these anomalies. This proposal does not resist a critical examination.