Dynamical disentangling and cooling of atoms in bilayer optical lattices

Abstract

We show how experimentally available bilayer lattice systems can be used to prepare quantum many-body states with exceptionally low entropy in one layer, by dynamically disentangling the two layers. This disentangling operation moves one layer - subsystem $A$ - into a regime where excitations in $A$ develop a single-particle gap. As a result, this operation maps directly to cooling for subsystem $A$, with entropy being shuttled to the other layer. For both bosonic and fermionic atoms, we study the dynamics of this process, and show that disentangling can be realised cleanly in ongoing optical lattice experiments. The corresponding entanglement entropies are directly measurable with quantum gas microscopes, and as a tool for producing lower-entropy states, this technique opens a range of applications beginning with simplifying production of anti-ferromagnetically ordered states of fermions.