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

In this paper we study in detail different types of topological solitons that are possible in bilayer quantum Hall systems at filling fraction nu =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 functional and their consequences are examined. Then we identify permissible classes of finite energy solutions that are topologically nontrivial. We also numerically evaluate 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.