# Spontaneous stripe order at certain even-denominator fractions in the lowest Landau level

**Authors:** Seung-Yeop Lee, Vito W. Scarola, J. K. Jain  
**arXiv:** [cond-mat/0104210](https://arxiv.org/abs/cond-mat/0104210)  
**Date:** 2001-04-11  
**Summary page:** https://www.summarizepaper.com/en/paper/cond-mat--0104210v1/

## Key points

- Study investigates physics of lowest Landau level at even-denominator fractions
- Previous research explained behavior of half or quarter-filled levels using Fermi sea of composite fermions
- Nature of state at other even-denominator fractions unclear
- Authors focus on Landau level fillings corresponding to composite fermion fillings $\nu^*=n+1/2$
- Two potential states ruled out: composite-fermion Fermi sea and paired composite-fermion state
- System predicted to undergo phase separation into stripes of $n$ and $n+1$ filled Landau levels
- Study provides insights into behavior of even-denominator fractions by ruling out certain states and proposing phase separation mechanism
- Contributes to understanding of complex quantum systems.

## Summary

This study investigates the physics of the lowest Landau level at even-denominator fractions, specifically those of the form $\nu=(2n+1)/(4n+4)$. Previous research has successfully explained the behavior of half or quarter-filled lowest Landau levels in terms of a Fermi sea of composite fermions. However, the nature of the state at other even-denominator fractions has remained unclear. To address this gap in knowledge, the authors focus on Landau level fillings that correspond to composite fermion fillings $\nu^*=n+1/2$ and consider various plausible candidate states. Through their analysis, they rule out two potential states: the composite-fermion Fermi sea and paired composite-fermion state. Instead, they predict that the system undergoes phase separation into stripes consisting of $n$ and $n+1$ filled Landau levels of composite fermions. Overall, this study provides valuable insights into the behavior of even-denominator fractions in the lowest Landau level by ruling out certain states and proposing a phase separation mechanism. It contributes to our understanding of complex quantum systems.