Origin of Hall Anomaly in the Mixed State

TL;DR

This paper discusses the origin of the Hall anomaly in the mixed state of superconductors, emphasizing the role of vortex many-body effects and pinning, and critiques existing microscopic theories as mathematically incorrect.

Contribution

It clarifies that existing vortex many-body theories can explain D'Anna et al.'s data and critiques the mathematical validity of other microscopic theories.

Findings

D'Anna et al.'s data align with vortex many-body effect theories.

Existing microscopic theories are mathematically flawed.

Recognition of the importance of vortex effects in Hall anomaly interpretation.

Abstract

There has been a corporative absence of understanding of Hall anomaly data in the mixed state in terms of vortex many-body effect and pinning, because of the dominant theoretical influence. Now D'Anna et al. [ Phys. Rev. Lett. 81, 2530 (1998) (cond-mat/9808164)] are brave enough to announce the prominent role played by vortex many-body effect and pinning in their interpretation of their own data. Here I wish to point out: (1) Indeed the data of D'Anna et al. can be explained within an existing Hall anomaly theory based on vortex many-body considerations; (2) It is not surprising that their data are not consistent with available microscopic Hall anomaly theories, because those theories are mathematically incorrect; and (3) The courage of D'Anna et al. should be appreciated.