Rotating molecules as quantum magnets

Abstract

The push to engineer and probe quantum many-body systems using ultracold gases has reached a milestone with the observation of controlled dynamics caused by interactions between distant molecules trapped in a lattice. See Letter p.521 The long-range dipolar interactions between polar molecules in ultracold molecular gases allow the spin dynamics to be fully decoupled from motion of the molecules — an attractive feature for the realization of lattice spin models for exploring quantum magnetism. Measured effects of such dipolar interactions have so far been limited to the modification of inelastic collisions and chemical reactions. Here the authors use dipolar interactions of polar molecules pinned in a three-dimensional optical lattice to realize a lattice spin model. The results open the possibility of realizing a wide range of spin models with long-range interaction, and lay the groundwork for future studies of many-body dynamics in spin lattices.