Effective Hamiltonians for holes in antiferromagnets: a new approach to implement forbidden double occupancy

Abstract

A coherent state representation for the electrons of ordered antiferromagnets is used to derive effective Hamiltonians for the dynamics of holes in such systems. By an appropriate choice of these states, the constraint of forbidden double occupancy can be implemented rigorously. Using these coherent states, one arrives at a path integral representation of the partition function of the systems, from which the effective Hamiltonians can be read off. We apply this method to the t-J model on the square lattice and on the triangular lattice. In the former case, we reproduce the well-known fermion-boson Hamiltonian for a hole in a collinear antiferromagnet. We demonstrate that our method also works for non-collinear antiferromagnets by calculating the spectrum of a hole in the triangular antiferromagnet in the self-consistent Born approximation and by comparing it with numerically exact results.

9 pages, Latex, 6 figures

Cited by in corpus (9)

• Indications of Unconventional Superconductivity in Doped and Undoped Triangular Antiferromagnets
• Systematic Low-Energy Effective Theory for Magnons and Charge Carriers in an Antiferromagnet
• Two-Hole Bound States from a Systematic Low-Energy Effective Field Theory for Magnons and Holes in an Antiferromagnet
• Quasiparticle vanishing driven by geometrical frustration
• Holes and magnetic polarons in a triangular lattice antiferromagnet
• Spin polarons in triangular antiferromagnets
• Hole and electron dynamics in the triangular-lattice antiferromagnet -- interplay of frustration and spin fluctuations
• Spectral Function in Mott Insulating Surfaces
• Single-hole dynamics in the t-J model