Stability of the Excitonic Phase in Bilayer Quantum Hall Systems at Total Filling One -- Effects of Finite Well Width and Pseudopotentials --

TL;DR

This study investigates the stability of the excitonic phase in bilayer quantum Hall systems at total filling factor one, highlighting how finite layer thickness and specific pseudopotential interactions influence phase stability and destruction.

Contribution

It derives pseudopotential parameters for finite layer thickness and analyzes how intra-layer interactions affect the excitonic phase stability.

Findings

Finite thickness enhances excitonic phase stability.

Intra-layer pseudopotentials can destroy the excitonic phase.

Intra-layer repulsion at twice the magnetic length is critical for phase destruction.

Abstract

The ground state of a bilayer quantum Hall system at $\nu_{\rm T}=1$ with model pseudopotential is investigated by the DMRG method. Firstly, pseudopotential parameters appropriate for the system with finite layer thickness are derived, and it is found that the finite thickness makes the excitonic phase more stable. Secondly, a model, where only a few pseudopotentials with small relative angular momentum have finite values, is studied, and it is clarified how the excitonic phase is destroyed as intra-layer pseudopotential becomes larger. The importance of the intra-layer repulsive interaction at distance twice of the magnetic length for the destruction of the excitonic phase is found.