# Reply to Comment on "Magnetotransport signatures of a single nodal electron pocket constructed from Fermi arcs"

## TL;DR

This paper defends the validity of a biaxially reconstructed Fermi surface pocket model in underdoped cuprates, addressing critiques about its geometry, quantum oscillations, and physical plausibility, supported by experimental evidence.

## Contribution

It provides a detailed response affirming the robustness of the diamond-shaped Fermi pocket model against critiques, reinforcing its consistency with experimental observations.

## Key findings

- The Hall coefficient sign change is not dependent on vertex rounding.
- A single diamond-shaped pocket can produce quantum oscillations in R_H.
- A reconstructed Fermi surface with one pocket is physically plausible.

## Abstract

In a recent manuscript, we showed how an electron pocket in the shape of a diamond with concave sides could potentially explain changes in sign of the Hall coefficient R_H in the underdoped high-Tc cuprates as a function of magnetic field and temperature. For simplicity, this Fermi surface is assumed to be constructed from arcs of a circle connected at vertices which is an idea borrowed from Banik and Overhauser. Such a diamond-shaped pocket is proposed to be the product of biaxial charge-density wave order, which was subsequently confirmed in x-ray scattering experiments. Since those x-ray scattering experiments were performed, the biaxial Fermi surface reconstruction scheme has garnered widespread support in the scientific literature. It has been shown to accurately account for the cross-section of the Fermi surface pocket observed in quantum oscillation measurements, the sign and behavior of the Hall coefficient, the size of the high magnetic field electronic contribution to the heat capacity and more recently the form of the angle-dependent magnetoresistance.In their comment, Chakravarty and Wang raise several important questions relating to the validity of the Hall coefficient we calculated for such a diamond-shaped Fermi surface pocket. These questions concern specifically (1) whether a change in sign of the Hall coefficient R_H with magnetic field and temperature is dependent on a `special' form for the rounding of the vertices, (2) whether a pocket of such a geometry can produce quantum oscillations in R_H in the absence of other Fermi surface sections and (3) whether a reconstructed Fermi surface consisting of a single pocket is less `natural' than one consisting of multiple pockets. Below we consider each of these in turn.