A 2D spin-ice model exhibiting a Kasteleyn transition

We present an Ising model on a two-dimensional lattice with mixed ferro- and antiferromagnetic nearest-neighbor and next-nearest-neighbor exchange couplings. We show that this model exhibits 'spin ice' behavior, retaining a non-zero entropy density even at zero temperature. We further demonstrate that, in the presence of an applied longitudinal magnetic field, it undergoes a Kasteleyn (line-defect-driven) transition from a fully magnetized to a 'stringy' phase upon heating. Finally, we discuss directions for further work, including the possibility of deforming our model into one exhibiting a quantum Kasteleyn transition.