Realization of a Bosonic Antiferromagnet

TL;DR

This paper reports the creation and observation of a one-dimensional bosonic antiferromagnetic Heisenberg model using ultracold atoms, enabling detailed studies of quantum magnetism in a highly controllable system.

Contribution

It demonstrates the realization of a bosonic antiferromagnet in an extended optical lattice and introduces optimized adiabatic techniques to approach low-entropy antiferromagnetic states.

Findings

Successfully created a 70-site bosonic antiferromagnetic chain.

Measured the evolution of staggered magnetization and spin correlations.

Showed advantages of ultracold gases for studying quantum magnetism.

Abstract

Quantum antiferromagnets are of broad interest in condensed matter physics as they provide a platform for studying exotic many-body states including spin liquids and high-temperature superconductors. Here, we report on the creation of a one-dimensional Heisenberg antiferromagnet with ultracold bosons. In a two-component Bose-Hubbard system, we switch the sign of the spin-exchange interaction and realize the isotropic antiferromagnetic Heisenberg model in an extended 70-site chain. Starting from a low-entropy N\'eel-ordered state, we use optimized adiabatic passage to approach the bosonic antiferromagnet. We demonstrate the establishment of antiferromagnetism by probing the evolution of the staggered magnetization and spin correlations of the system. Compared with condensed matter systems, ultracold gases in optical lattices can be microscopically engineered and measured, offering significant advantages for exploring bosonic magnetism and spin dynamics.