Dynamical disentangling and cooling of atoms in bilayer optical lattices

TL;DR

This paper proposes a method to cool and prepare low-entropy quantum states in bilayer optical lattices by dynamically disentangling the layers, effectively transferring entropy away from the target layer.

Contribution

It introduces a novel disentangling technique in bilayer systems that enables efficient cooling and low-entropy state preparation for quantum many-body experiments.

Findings

Disentangling maps to cooling by transferring entropy to the second layer.

The process is feasible with current optical lattice experiments.

Entanglement entropy measurements are accessible with quantum gas microscopes.

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.