Skyrmion and Bimeron Excitations in Imbalanced Bilayer Quantum Hall Systems

Abstract

Skyrmion excitations are analyzed in imbalanced bilayer quantum Hall systems based on a microscopic theory. A skymion carries both the spin and pseudospin degrees of freedom. In the presence of the parallel magnetic field, the activation energy increases due to the spin component, while it decreases due to the pseudospoin component by deforming a skyrmion into a bimeron (a pair of merons). We propose an approximate formula for the activation energy in imbalanced systems.