Charged pseudospin textures in double-layer quantum Hall systems: Bimerons and meron crystals

Quasiparticle excitations of incompressible quantum nail stales at a total filling factor tor nu = 1 in a double-layer system have bimeron pseudospin textures. We studied the charge and pseudospin distributions and the energies of these quasiparticles as a function of layer separation, tunneling amplitude between the layers, and in-plant magnetic field strength by using a supercell microscopic unrestricted Hartree-Fock approach. We find that for typical double-layer system parameters, estimates of quasiparticle properties based wholly or partly on field-theoretic models require substantial quantitative revision. We comment on the nature of the crystal states expected at a finite but small quasiparticle density, and on limitations of the unrestricted Hartree-Fock approach.