Spontaneous Pseudospin Spiral Order in Bilayer Quantum Hall Systems

TL;DR

This paper demonstrates the emergence of a spontaneous pseudospin spiral order in bilayer quantum Hall systems at total filling factor 1, revealing a new form of long-range interlayer phase coherence beyond the pseudospin ferromagnetic phase.

Contribution

It introduces the concept of spontaneous pseudospin spiral order in bilayer quantum Hall systems and distinguishes it from pseudospin ferromagnetic order, based on exact diagonalization results.

Findings

Identification of a new long-range interlayer phase coherence

Existence of pseudospin spiral order at larger interlayer distances

Distinction between phase coherence and ferromagnetic order

Abstract

Using exact diagonalization of bilayer quantum Hall systems at total filling factor $\nu_T=1$ in the torus geometry, we show that there is a new long-range interlayer phase coherence due to spontaneous pseudospin spiral order at interlayer distances larger than the critical value at which the pseudospin ferromagnetic order is destroyed. We emphasize the distinction between the interlayer phase coherence and the pseudospin ferromagnetic order.