Entangled states from sparsely coupled spins for metrology with neutral atoms

TL;DR

This paper demonstrates that highly entangled states for quantum metrology can be generated using sparse, long-range interactions among neutral atoms, reducing the complexity of interactions needed for optimal sensing.

Contribution

It introduces a method to produce optimal quantum sensing states with sparse, logarithmic couplings, approximating all-to-all models for large systems.

Findings

Sparse graphs with long-range interactions can mimic all-to-all spin dynamics.

Optimal entangled states can be generated with fewer interactions per particle.

The protocol is implementable with optical tweezers and dynamic atom reconfiguration.

Abstract

Quantum states featuring extensive multipartite entanglement are a resource for quantum-enhanced metrology, with sensitivity up to the Heisenberg limit. However, robust generation of these states using unitary dynamics typically requires all-to-all interactions among particles. Here, we demonstrate that optimal states for quantum sensing can be generated with sparse interaction graphs featuring only a logarithmic number of couplings per particle. We show that specific sparse graphs with long-range interactions can approximate the dynamics of all-to-all spin models, such as the one-axis twisting model, even for large system sizes. The resulting sparse coupling graphs and protocol can also be efficiently implemented using dynamic reconfiguration of atoms in optical tweezers.