Short answer: A quantum spin liquid is an exotic phase of matter with long-range entanglement, and Rydberg atom arrays are being proposed as a platform to realise one. A 2021 experiment is reported to have shown preliminary signs of a Z2 spin liquid, and three theory papers propose other spin liquids in pyrochlore and honeycomb arrays. The proposals are calculations, not experiments.

What a spin liquid is

A 2025 Physical Review X paper describes quantum spin liquids as exotic phases whose low-energy physics is described as the deconfined phase of an emergent gauge theory. A 2023 Communications Physics paper calls them elusive but paradigmatic strongly correlated quantum states characterised by long-range quantum entanglement.

Experimental signs

Both the 2025 and 2023 papers refer to an experiment, by Semeghini and co-workers in Science in 2021, that showed preliminary signs of Z2 topological order in a system of Rydberg atoms. The 2023 paper describes this as signatures of a gapped topological Z2 spin liquid. These papers treat that as a starting point rather than a settled result, and their own contributions are proposals.

A three-dimensional U(1) spin liquid

The 2025 paper proposes realising a U(1) quantum spin liquid in three spatial dimensions, described by the deconfined phase of a U(1) gauge theory, in a pyrochlore-lattice Rydberg array. The authors study the ground-state phase diagram as a function of experimentally relevant parameters. In their calculation, tuning the Rabi frequency gives access to both the confinement-deconfinement transition driven by proliferation of magnetic monopoles, and the Higgs transition driven by proliferation of electric charges of the emergent gauge theory.

A trimer spin liquid

The 2023 paper proposes a different class of spin liquid in a honeycomb array of Rydberg atoms. Using density-matrix renormalisation group and exact diagonalisation, the authors map the phase diagram and identify several density-wave-ordered phases and a trimer spin liquid ground state with an emergent U(1) x U(1) local symmetry. The liquid arises from superpositions of classical trimer configurations on the dual triangular lattice when third-nearest-neighbour atoms lie within the Rydberg blockade radius. They go on to discuss conditions for its realisation.

A Kitaev chiral spin liquid

A Physical Review Research paper proposes realising and detecting the Kitaev chiral spin liquid, noted for its non-Abelian excitations, in a deformed honeycomb array. A laser-assisted dipole-dipole interaction provides effective hopping and pairing terms for hard-core bosons, which with van der Waals interactions gives the pure Kitaev model with high precision, according to the authors. They propose detecting chiral Majorana edge modes by light Bragg scattering and by imaging their chiral motion.

Limits

All three papers are theory proposals based on numerical calculations and model assumptions. Whether the proposed phases can be prepared and detected in experiments is not shown in them.

FAQ

What is a quantum spin liquid?

A phase with long-range entanglement described by an emergent gauge theory, per the 2025 paper.

Has one been seen in Rydberg arrays?

The papers cite a 2021 experiment with preliminary signs of Z2 topological order.

What do the new papers add?

Proposals for U(1), trimer and Kitaev chiral spin liquids.

Are the proposals tested?

No. They are calculations and schemes.

Why Rydberg atoms?

The papers describe Rydberg arrays as a promising, controllable platform for these phases.

All field notes