Onset of Interlayer Phase Coherence in a Bilayer Two-Dimensional Electron System: Effect of Layer Density Imbalance

TL;DR

This study investigates how layer density imbalance affects the onset of interlayer phase coherence in bilayer 2D electron systems, revealing that imbalance shifts the phase boundary and increases the critical layer separation quadratically.

Contribution

It demonstrates that layer density imbalance influences the phase boundary, providing new insights into the conditions for interlayer coherence in bilayer electron systems.

Findings

Phase boundary shifts to larger separations with imbalance

Critical layer separation increases quadratically with density difference

Interlayer coherence is sensitive to density imbalance

Abstract

Tunneling and Coulomb drag are sensitive probes of spontaneous interlayer phase coherence in bilayer two-dimensional electron systems at total Landau level filling factor $\nu_T = 1$. We find that the phase boundary between the interlayer phase coherent state and the weakly-coupled compressible phase moves to larger layer separations as the electron density distribution in the bilayer is imbalanced. The critical layer separation increases quadratically with layer density difference.