# Vestigial nematicity from spin and/or charge order in the cuprates

## TL;DR

This paper develops an effective field theory for layered cuprates showing how nematic order emerges from intertwined spin and charge density waves, influenced by temperature, disorder, and material-specific parameters.

## Contribution

It introduces a variational approach to study nematicity arising from melting spin and charge density waves in cuprates, accounting for material differences.

## Key findings

- Nematic phase appears as temperature decreases.
- Fluctuations reflect either SDW or CDW order depending on parameters.
- Material-specific differences in SDW-CDW interplay are discussed.

## Abstract

Nematic order has manifested itself in a variety of materials in the cuprate family. We propose an effective field theory of a layered system with incommensurate, intertwined spin- and charge-density wave (SDW and CDW) orders, each of which consists of two components related by $C_4$ rotations. Using a variational method (which is exact in a large $N$ limit), we study the development of nematicity from partially melting those density waves by either increasing temperature or adding quenched disorder. As temperature decreases we first find a transition to a nematic phase, but depending on the range of parameters (e.g. doping concentration) the strongest fluctuations associated with this phase reflect either proximate SDW or CDW order. We also discuss the changes in parameters that can account for the differences in the SDW-CDW interplay between the (214) family and the other hole-doped cuprates.