Simultaneous Excitation of Spins and Pseudospins in the Bilayer $\nu=1$ Quantum Hall State

TL;DR

This study investigates how tilting the magnetic field affects the energy gap in bilayer quantum Hall states at filling factor 1, revealing a continuous transition from bilayer to monolayer states and exploring spin-pseudospin interactions.

Contribution

It provides experimental evidence of the continuous evolution of the energy gap with density imbalance and discusses the interplay of spins and pseudospins in quantum Hall ferromagnets.

Findings

Energy gap varies continuously with density imbalance.

Even high tunneling gap samples show the same activation energy anomaly.

Possible link between experimental results and spin-pseudospin quantum Hall ferromagnet.

Abstract

The tilting angular dependence of the energy gap was measured in the bilayer quantum Hall state at the Landau level filling $\nu=1$ by changing the density imbalance between the two layers. The observed gap behavior shows a continuous transformation from the bilayer balanced density state to the monolayer state. Even a sample with 33 K tunneling gap shows the same activation energy anomaly reported by Murphy {\it et al.}. We discuss a possible relation between our experimental results and the quantum Hall ferromagnet of spins and pseudospins.