Simulating dipole-dipole interactions on the hyperkagome lattice, a new spin ice

Abstract

Motivated by studies of non-magnetic dopings of pyrochlore spin ice and the experimental realization of the hyperkagome lattice in Na4Ir3O8, this work studies the dipolar ice model on the hyperkagome lattice. This is a local <111> Ising model with classical spins featuring an antiferromagnetic neighbour exchange as well as a long range dipolar interaction, previously studied on the pyrochlore lattice. A hybrid single spin flip/loop algorithm Monte Carlo code has been developed to address ergodicity issues seen at low temperatures. This algorithm agrees with analytical results for the smallest system size and has been extended to larger system sizes. A phase diagram very similar to that of the pyrochlore lattice is found with an antiferromagnetic region as well as regions with a spin ice crossover and a low temperature ordering transition. An additional charge-ordered state, similar to that in the recently studied kagome spin ice, was also found.