2D ISING MODEL WITH COMPETING INTERACTIONS AND ITSAPPLICATION TO CLUSTERS AND ARRAYS OF π-RINGS,GRAPHENE AND ADIABATIC QUANTUM COMPUTING

摘要

We study the two-dimensional Ising model with competing nearest-neighbour and di-agonal interactions and investigate the phase diagram of this model. We show that theground state at low temperatures is ordered either as stripes or as the Neel antiferro-magnet. However, we also demonstrate that the energy of defects and dislocations inthe lattice is close to the ground state of the system. Therefore, many locally stable (ormetastable) states associated with local energy minima separated by energy barriers mayappear forming a glass-like state.