Agenda

The face-centered-cubic (fcc) lattice is one of the most abundant crystal structures in nature. There are numerous examples of fcc magnetic materials relevant to specific technological applications as well as to the recent search for quantum spin liquids in 3D spin systems. I use spin-wave theory to analyze the J₁-J₂ fcc Heisenberg antiferromagnet, which offers a fertile ground for many interesting physical phenomena around its phase diagram. In particular, I demonstrate that magnon-magnon interactions have a dramatic effect in the nearest-neighbor case, producing a highly non-trivial quantum order by disorder ground state selection.