Observation Of Constructive Interference At The Edge Of Quantum Ergodicity Dmitry A Abanin Rajeev Acharya Laleh Aghababaiebeni Georg Aigeldinger Ashok Ajoy Ross Alcaraz Igor Aleiner Trond I Andersen Markus Ansmann Frank Arute Kunal Arya Abraham Asfaw Nikita Astrakhantsev Juan Atalaya Ryan by Dmitry A. Abanin & Rajeev Acharya & Laleh Aghababaie-beni & Georg Aigeldinger & Ashok Ajoy & Ross Alcaraz & Igor Aleiner & Trond I. Andersen & Markus Ansmann & Frank Arute & Kunal Arya & Abraham Asfaw & Nikita Astrakhantsev & Juan Atalaya & Ryan… instant download after payment.

The dynamics of quantum many-body systems is characterized by quantum Published online: 22 October 2025observables that are reconstructed from correlation functions at separate points in Open accessspace and time1–3. In dynamics with fast entanglement generation, however, quantum observables generally become insensitive to the details of the underlying dynamics at Check for updateslong times due to the efects of scrambling. To circumvent this limitation and enable access to relevant dynamics in experimental systems, repeated time-reversal protocols have been successfully implemented4. Here we experimentally measure the secondorder out-of-time-order correlators (OTOC(2))5–18 on a superconducting quantum processor and fnd that they remain sensitive to the underlying dynamics at long timescales. Furthermore, OTOC(2) manifests quantum correlations in a highly entangled quantum many-body system that are inaccessible without time-reversal techniques. This is demonstrated through an experimental protocol that randomizes the phases of Pauli strings in the Heisenberg picture by inserting Pauli operators during quantum evolution. The measured values of OTOC(2) are substantially changed by the protocol, thereby revealing constructive interference between Pauli strings that form large loops in the confguration space. The observed interference mechanism also endows OTOC(2) with high degrees of classical simulation complexity. These results, combined with the capability of OTOC(2) in unravelling useful details of quantum dynamics, as shown through an example of Hamiltonian learning, indicate a viable path to practical quantum advantage.