We present a systematic study of the Hall conductance in Bi2Sr2CaCu2Ox (Bi2212) thin films over a large range of doping. We find that in a large part of the phase diagram the Hall coefficient changes sign as a function of temperature in the flux-flow regime. By comparing data from many samples, we show that the sign reversal is tied to the superconducting transition and is not a result of a competing order. We then compare our data to the predictions of the Bardeen-Stephan model and show that in all samples there is an additional negative contribution to the Hall conductivity. We extract from the negative excess Hall a vortex-charge that is found to be strongly doping dependent.
@article{arxiv.2304.03028,
title = {Hall anomaly and vortex charge in Bi$_2$Sr$_2$CaCu$_2$O$_x$},
author = {Yuval Nitzav and Amit Kanigel},
journal= {arXiv preprint arXiv:2304.03028},
year = {2023}
}