Non Hermitian Ssh Charge Correlations

---
name: non-hermitian-ssh-charge-correlations
description: Enhancement of charge correlations and topological markers in interacting non-Hermitian Su-Schrieffer-Heeger models.
platforms: [linux, macos, windows]
tags: [non-hermitian, topology, SSH-model, charge-density-wave, exceptional-points]
arxiv: 2606.06466
---

# Non-Hermitian SSH Model Charge Correlations

**Paper**: arXiv:2606.06466 - "Enhancement of charge correlations and real-space topological marker on an interacting non-Hermitian Su-Schrieffer-Heeger model"
**Authors**: Sebastião dos A. Sousa-Júnior et al.
**Date**: 2026-06-04

## Core Methodology

Investigation of **topology-charge ordering interplay** in interacting non-Hermitian SSH model with:
- Real-space topological marker diagnostics
- Enhanced charge correlations near exceptional points
- Open boundary condition amplification

## Key Findings

### Topological Phase Mapping

- **Real-space topological marker**: Robust diagnostic of non-Hermitian topological phases
- **Interaction presence**: Marker remains reliable under interactions
- **CDW onset**: Marker signals topological phase breakdown

### Non-Hermiticity Enhancement

**Open boundary conditions (OBC)** lead to:
- **Pronounced amplification** of staggered charge correlations
- Enhanced interaction effects near exceptional points
- **Electronic instabilities** promoted by low-energy state accumulation

### Periodic vs Open Boundary Conditions

- **Periodic boundary conditions (PBC)**: Moderate changes
- **Open boundary conditions (OBC)**: Dramatic enhancement
- **Key difference**: Exceptional point proximity effects

## Technical Framework

### SSH Model with Non-Hermiticity

- **Standard SSH**: Hermitian Su-Schrieffer-Heeger model
- **Non-Hermitian extension**: Complex hopping terms
- **Interactions**: Charge ordering effects included

### Phase Diagnostics

1. **Topological marker**: Real-space diagnostic
2. **Charge correlations**: Staggered density measurements
3. **Complex spectrum**: Many-body eigenvalue analysis
4. **Phase diagram**: Topology vs CDW mapping

### Exceptional Point Effects

- **Low-energy state accumulation**: Near exceptional points
- **Electronic instabilities**: Enhanced by exceptional point proximity
- **CDW strengthening**: Amplified charge density wave tendencies

## Key Results

### Topological Robustness

- Topological marker works under interactions
- Consistent signal for topological phase breakdown
- Reliable diagnostic for non-Hermitian topology

### Boundary Condition Effects

- OBC dramatically enhances charge correlations
- PBC shows moderate effects
- Exceptional points amplify differences

### Interaction Enhancement

- Non-Hermiticity amplifies interaction effects
- CDW onset strengthened near exceptional points
- Electronic instabilities promoted

## Implementation Approach

### Phase Diagram Construction

1. Calculate real-space topological marker
2. Measure charge correlations
3. Analyze complex many-body spectrum
4. Map topology vs CDW phases

### Boundary Condition Study

- Compare PBC vs OBC results
- Analyze exceptional point effects
- Measure correlation amplification

## Research Applications

- Non-Hermitian topology studies
- Charge ordering in quantum systems
- Exceptional point physics
- Topological phase transitions
- Interacting non-Hermitian systems

## Related Skills

- [[non-hermitian-quantum-systems]] - Non-Hermitian physics
- [[topological-quantum-states]] - Topology in quantum systems
- [[exceptional-points-quantum]] - Exceptional point phenomena

## References

- arXiv:2606.06466 - Original paper
- SSH model literature - Su-Schrieffer-Heeger model
- Non-Hermitian topology - Exceptional points and topology

**Activation**: non-hermitian, SSH-model, topology, charge-correlations, exceptional-points, CDW