Autonomous Stabilization of Photonic Many-Body Systems

Brendan Saxberg, Alex Ma, Clai Owens +3 more

Brendan Saxberg, J.M. Owens, Ruichao Ma +2 more

Charlotte Franke, Dorian A. Gangloff

Reaching a technological advantage with large quantum systems requires safeguarding their many-body entanglement. Dissipation typically acts to decohere a quantum system via random projective noise but, when judiciously engineered together with coherent interactions, it can funnel the system towards a target entangled state. The native interactions and dissipative channels available to most systems are, however, difficult to combine effectively. Here we propose interleaving Floquet Hamiltonian engineering, which allows the construction of non-native coherent interactions, with weak measurement, which enables a tuneable dissipative channel, to enable programmable and autonomous stabilization of many-body entanglement. We show this analytically and numerically for the central-spin system of a semiconductor quantum dot, for which we construct spin-squeezed and Schrödinger-cat states that are stabilized against realistic levels of dephasing. Our approach is applicable to any system compatible with periodic drives and tuneable measurement strength and could enable novel approaches to practical error correction.

Brendan Saxberg, Ruichao Ma, Clai Owens +2 more

Emile I. Haddad

F. Q. Guo, Shi-Lei Su, Weibin Li +1 more

Autonomous stabilization of many-body quantum states requires a mechanism that continuously removes stabilizer violations without relying on measurement and feedback. Here we develop a Floquet-Lindblad framework for scalable stabilizer pumping in neutral Rydberg atom arrays. Periodically modulated Rydberg excitation selectively couples the negative-eigenvalue sector of a prescribed stabilizer to auxiliary Rydberg states, while engineered dissipation irreversibly transfers the population into the corresponding positive-eigenvalue sector and leaves the target stabilizer manifold dark. This establishes a modular pumping primitive that can be composed to autonomously stabilize general many-body stabilizer manifolds, rather than merely prepare a specific entangled state. The combination of Floquet-selective excitation and fast engineered dissipation accelerates convergence, while transient single-Rydberg excitation and suppressed real multi-Rydberg occupation reduce sensitivity to Rydberg-state loss, blackbody-radiation-induced leakage, and spatial fluctuations. We demonstrate the framework through Bell and multiqubit graph states, including parallel stabilizer pumping that reduces the convergence time for the simulated multiqubit systems. The same dissipative attraction also enables purification of imperfect resource states. These results establish Floquet-engineered stabilizer pumping as a scalable route toward autonomous quantum-state stabilization and protected entanglement generation in neutral-atom platforms.