The means to make the toric code, or the planar code, into a fully self-correcting quantum memory is often considered. Self-correction means that the Hamiltonian will naturally suppress errors indefinitely, leading to a lifetime that diverges in the thermodynamic limit. It has been found that this is possible in the toric code only if long range interactions are present between anyons. Proposals have been made for realization of these in the lab Another approach is the generalization of the model to higher dimensions, with self-correction possible in 4D with only quasi-local interactions.