# Pair Density Wave Instability in the Kagome Hubbard Model

**Authors:** Tilman Schwemmer, Hendrik Hohmann, Matteo Dürrnagel, Janik Potten, Jacob Beyer, Stephan Rachel, Yi-Ming Wu, Srinivas Raghu, Tobias Müller, Werner Hanke, Ronny Thomale  
**arXiv:** [2302.08517](https://arxiv.org/abs/2302.08517)  
**Date:** 2023-02-16  
**Summary page:** https://www.summarizepaper.com/en/paper/2302.08517v1/

## Key points

- Study title: "Pair Density Wave Instability in the Kagome Hubbard Model"
- Investigate behavior of electrons on a kagome lattice under onsite Hubbard $U$ and nearest neighbor $V$ interactions
- Identify pair density wave (PDW) instability coexisting with $d$-wave superconducting (SC) instability at zero lattice momentum
- PDW characterized by intra-unit cell modulations of pairing function
- Competition between PDW and $d$-wave SC instabilities influenced by interaction strength and coupling ratio $V/U$
- At weak coupling strengths, observe intra-unit cell modulated vestigial charge density wave alongside $s$-wave SC instability
- Provides insights into microscopic mechanisms underlying PDW formation
- Contributes to understanding unconventional electronic phases in correlated materials on complex lattices like kagome

## Summary

In their study titled "Pair Density Wave Instability in the Kagome Hubbard Model," authors Tilman Schwemmer, Hendrik Hohmann, Matteo Dürrnagel, Janik Potten, Jacob Beyer, Stephan Rachel, Yi-Ming Wu, Srinivas Raghu, Tobias Müller, Werner Hanke and Ronny Thomale investigate the behavior of electrons on a kagome lattice under onsite Hubbard $U$ and nearest neighbor $V$ interactions. Through a functional renormalization group analysis, they identify a pair density wave (PDW) instability that coexists with a $d$-wave superconducting (SC) instability at zero lattice momentum. The distinguishing feature of the PDW is its intra-unit cell modulations of the pairing function. The competition between the PDW and $d$-wave SC instabilities is influenced by the absolute strength of interaction and the coupling ratio $V/U$. In regions adjacent to this domain at weak coupling strengths <un>,</un> researchers observe an intra-unit cell modulated vestigial charge density wave alongside an $s$-wave SC instability. This comprehensive study provides valuable insights into the microscopic mechanisms underlying PDW formation in a controlled limit. By exploring the interplay between different types of instabilities in electron systems on complex lattices like kagome <un>,</un> authors contribute to our understanding of unconventional electronic phases and their emergence in correlated materials. The findings presented in this work offer a significant step towards unraveling the intricate physics governing quantum phenomena in condensed matter systems.