Abstract
The melting and magnetic disordering of the Skyrmion lattice in the quantum Hall system at filling factor are studied. A Berezinskii-Kosterlitz-Thouless renormalization-group theory is employed to describe the coupled magnetic and translational degrees of freedom. The nontrivial magnetic properties of the Skyrmion system stem from the in-plane components of the noncollinear magnetization in the vicinity of Skyrmions, which are described by an antiferromagnetic model. In a Coulomb gas formulation the “particles” are the topological defects of the model (vortices) and of the lattice (dislocations and disclinations). The latter frustrate the antiferromagnetic order and acquire fractional vorticity in order to minimize their energy. We find a number of melting/disordering scenarios for various lattice types. While these results do not depend on a particular model, we also consider a simple classical model for the Skyrmion system. It results in a rich phase diagram. We propose that the triangular and square Skyrmion lattices are generically separated by a centered rectangular phase in the quantum Hall system.
- Received 6 April 1998
DOI:https://doi.org/10.1103/PhysRevB.58.10634
©1998 American Physical Society