Spin-frustrated triangular system

Vibronic Interaction in a Spin-Frustrated Triangular System... 

The frustration effects are implicit in many physical systems, as different as spin glass magnets, adsorbed monomolecular films and liquid crystals [32, 54, 55], In the case of polar mesogens the dipolar frustrations may be modelled by a spin system on a triangular lattice (Fig, 5), The corresponding Hamiltonian consists of a two particle dipolar potential that has competing parallel dipole and antiparallel dipole interactions [321, The system is analyzed in terms of dimers and trimers of dipoles. When the dipolar forces between two of them cancel, the third dipole experiences no overall interaction. It is free to permeate out of the layer, thus frustrating smectic order. 

Antiferromagnetism on a triangular net is one of the problems of recent interest in the physics of spin systems. The main point is the frustration, i.e., existence of infinitely degenerate ground states. A typical example is CsCoClj (Mekata 1977, Mekata et al. 1986). 

---