Benchmarking dynamical-structure-factor protocols in programmable neutral-atom geometries

Measuring the dynamical structure factor (DSF) is essential for understanding the excitation spectra of quantum materials, but this task is computationally demanding for classical methods, especially in non-integrable or high-dimensional systems. This paper investigates whether programmable neutral-atom quantum processing units (QPUs) can serve as a reliable platform for measuring the DSF across a variety of Ising-like spin models.

The authors use numerical emulations of a neutral-atom QPU to benchmark a dynamical protocol for measuring the DSF. They test this protocol on several configurations: the standard 1D transverse-field Ising model (TFIM), a dimerized 1D SSH-Ising model, and the 2D TFIM. The study employs both state-vector emulators for smaller systems and matrix-product state (MPS) emulators for larger clusters. Crucially, the authors also incorporate a realistic noise model—accounting for laser fluctuations, positional disorder, and decoherence—to assess the protocol's feasibility in actual experimental settings.

The study demonstrates that the neutral-atom protocol successfully recovers the expected magnon bands in 1D systems. For the dimerized SSH-Ising model, the protocol captures the emergence of a spectral gap and identifies localized edge excitations. In the 2D TFIM, the authors show that the QPU protocol can access spectral properties in regimes where classical simulations become computationally expensive. Furthermore, the noise analysis reveals that while experimental imperfections lead to some broadening of the spectral features, the core excitation bands remain clearly identifiable, confirming the protocol's resilience to typical device noise.

This work provides a practical roadmap for using neutral-atom simulators to probe dynamical response functions in quantum systems that are currently beyond the reach of exact classical numerical methods. By validating the protocol against both integrable models and realistic noise, the authors pave the way for future experimental implementations that could offer new insights into the excitation spectra of complex quantum materials.