Long-range and frustrated spin-spin interactions in crystals of cold polar molecules

TL;DR

This paper presents a method to engineer and control long-range, tunable spin-spin interactions in crystals of cold polar molecules, enabling the study of complex quantum magnetic phases.

Contribution

It introduces a scheme using state-dependent dipole forces and lattice vibrations to realize and manipulate long-range, frustrated spin models in cold polar molecule crystals.

Findings

Demonstrates tunable long-range spin interactions via dipole modulation

Shows potential for creating multi-particle entangled states

Enables simulation of complex magnetic phases

Abstract

We describe a simple scheme for the implementation and control of effective spin-spin interactions in self-assembled crystals of cold polar molecules. In our scheme spin states are encoded in two long-lived rotational states of the molecules and coupled via state dependent dipole-dipole forces to the lattice vibrations. We show that by choosing an appropriate time dependent modulation of the induced dipole moments the resulting phonon-mediated interactions compete with the direct dipole-dipole coupling and lead to long-range and tunable spin-spin interaction patterns. We illustrate how this technique can be used for the generation of multi-particle entangled spin states and the implementation of spin models with longe-range and frustrated interactions which exhibit non-trivial phases of magnetic ordering.