Manifestation of the bulk phase transition in the edge energy spectrum in a two dimensional bilayer electron system

TL;DR

This study investigates how a bulk phase transition in a bilayer electron system affects its edge energy spectrum, revealing a close connection between bulk and edge states through non-linear I-V measurements.

Contribution

It demonstrates the manifestation of a bulk phase transition in the edge energy spectrum of a bilayer electron system using a quasi-Corbino geometry.

Findings

Edge energy spectrum closely linked to bulk phase transition.

Linear I-V curves at the transition indicate disappearance of the incompressible strip.

Edge spectrum reflects the bulk spin phase change.

Abstract

We use a quasi-Corbino sample geometry with independent contacts to different edge states in the quantum Hall effect regime to investigate the edge energy spectrum of a bilayer electron system at total filling factor $\nu=2$. By analyzing non-linear $I-V$ curves in normal and tilted magnetic fields we conclude that the edge energy spectrum is in a close connection with the bulk one. At the bulk phase transition spin-singlet - canted antiferromagnetic phase $I-V$ curve becomes to be linear, indicating the disappearance or strong narrowing of the $\nu=1$ incompressible strip at the edge of the sample.