Curator's Take
This article shows that a trapped‑ion processor can now tackle a classic condensed‑matter observable— the dynamical structure factor— by directly simulating both equilibrium preparation and real‑time dynamics on a 20‑site Heisenberg chain and even a realistic copper‑sulfate crystal. The authors’ “pumping” technique, which drives the system with an oscillating source term at a chosen frequency, sidesteps the heavy sampling costs of earlier Fourier‑transform methods and makes targeted frequency scans feasible on near‑term hardware. By linking quantum simulation to neutron‑scattering signatures, the work opens a practical pathway for quantum computers to complement experimental probes of material excitations.
— Mark Eatherly
Summary
Dynamical structure factors (DSF) measured with neutron-scattering experiments provide key insights into the structure of materials. Their computation requires both the preparation of an equilibrium state and the implementation of Hamiltonian dynamics. We demonstrate the feasibility of computing DSF on the Quantinuum Reimei trapped-ion quantum computer, comparing the DSF of 1D Heisenberg model on $20$ sites, and that of the copper sulfate crystal. To that end, we introduce a pumping approach for computing the DSF $S(q,ω)$ on quantum computers that enables targeting specific arbitrary values of frequencies $ω$. This method time-evolves the initial state using a time-dependent Hamiltonian perturbed by a source term oscillating at the target frequency $ω$. When targeting only a few frequency values, this approach provides a significant reduction in shot overhead compared to previous methods.