# Reply to P. Ao's Comment on "Sign reversing Hall effect in atomically thin high temperature superconductors"

## TL;DR

This paper refutes P. Ao's claim that vortex many-body effects cause Hall sign reversal in thin high-temperature superconductors, based on experimental evidence contradicting the theoretical predictions.

## Contribution

It provides experimental data that challenge the vortex many-body explanation for Hall sign reversal in atomically thin cuprate superconductors.

## Key findings

- Experimental results are incompatible with Ao's vortex effect predictions.
- Supports alternative mechanisms for Hall sign reversal.
- Clarifies the limitations of vortex many-body theories in this context.

## Abstract

We respond to P. Ao's comment in arXiv:1907.09263, which suggests that vortex many-body effects are the origin of Hall sign reversal in few-unit-cell thick Bi-2212 cuprate crystals (Phys. Rev. Lett. 122, 247001 (2019)). Our experimental results are incompatible with the theoretical predictions detailed in Ao's comment.