Quantum Hall solitons with intertwined spin and pseudospin at ν=1

Abstract

In this paper we study in detail different types of topological solitons that are possible in bilayer quantum Hall systems at filling fraction ν=1 when spin degrees of freedom are included. Starting from a microscopic Hamiltonian we derive an effective energy functional for studying such excitations. The gauge invariance and CP³ character of this energy fuctional and their consequences are examined. Then we identify permissible classes of finite energy solutions that are topologically nontrivial. We also numerically evaulate a representative solution in which a pseudospin (layer degrees of freedom) bimeron in a given spin component is intertwined with spin skyrmions in each layer and discuss whether it is energetically favored as the lowest-lying excitation in such system with some numerical results.