Spin jams, tiles, and frustrated magnets

Israel Klich (Virginia)

The phenomenon of frustration in spin systems usually leads to a large set of degenerate ground states, and thus to exotic spin states such as spin ice and spin liquid.

Motivated by puzzling behavior of frustrated magnetic systems such as SCGO, we describe how a system governed by simple Heisenberg interactions may freeze into a glass like state even in the absence of external disorder, which we call a spin jam. At the heart of the effect is an unusual scaling of the number of local minimum energy configuration. We establish these properties by a combination of tools and mappings, leading to a problem of counting tessellations. Finally, we report on a recent set of experiments exhibiting evidence for the proposed spin jam scenario.