Assembling a Bose-Hubbard superfluid from tweezer-controlled single atoms

TL;DR

This paper demonstrates a novel method to create a Bose-Hubbard superfluid from individually controlled atoms, enabling new quantum simulation capabilities with low-entropy many-body states.

Contribution

It introduces a new protocol for assembling itinerant many-body states from single atoms in an optical lattice, bridging the gap between isolated atoms and many-body quantum systems.

Findings

Prepared many-body states with approximately 2 k_B entropy per particle.

Achieved temperatures consistent with a significant superfluid fraction.

First demonstration of itinerant many-body systems assembled from rearranged atoms.

Abstract

Quantum simulation relies on the preparation and control of low-entropy many-body systems to reveal the behavior of classically intractable models. The development of new approaches for realizing such systems therefore represents a frontier in quantum science. Here we experimentally demonstrate a new protocol for generating ultracold, itinerant many-body states in a tunnel-coupled two-dimensional optical lattice. We do this by adiabatically connecting a near-ground-state-cooled array of up to 50 single strontium-86 atoms with a Bose-Hubbard superfluid. Through comparison with finite-temperature quantum-Monte-Carlo calculations, we estimate that the entropy per particle of the prepared many-body states is approximately $2 k_B$, and that the achieved temperatures are consistent with a significant superfluid fraction. This represents the first time that itinerant many-body systems have been prepared from rearranged atoms, opening the door to bottom-up assembly of a wide range of neutral-atom and molecular systems.