Probing information scrambling in a disordered dipolar Rydberg gas

Disordered dipolar Rydberg gases exhibit spin-glass–like behavior due to strong long-range couplings and interaction disorder. A central question is how disorder affects information scrambling under many-body dynamics. Out-of-time-order correlators (OTOCs) are a probe to quantify how a local spin perturbation spreads by measuring the growth of operators under forward and backward time evolution, thus requiring controlled time reversal to compare the system’s final state with its initial configuration.

Building on our demonstrated time-reversal protocol in a dipolar quantum many-body spin system, we implement a microwave-based scheme that reverses the sign of the dipolar interaction Hamiltonian.Under this seqence imperfections arise from higher-order terms in the effective Hamiltonian picture, including residual van der Waals interactions originating from higher-order Magnus contributions. We exploit these effects as a diagnostic tool and apply a dynamical decoupling–based control scheme to selectively suppress specific higher-order interaction terms.

This approach enables high-fidelity access to OTOCs in a disordered Rydberg spin glass and provides a route for benchmarking quantum simulators and assessing the role of higher-order interactions in analog quantum simulation.