Quantum error correction (QEC) and dynamical decoupling (DD) protect quantum information in complementary ways but their combination requires careful co-design. I will present a theory that identifies when a hybrid approach helps along with an experiment on IBM transmon processors that puts it to the test. The theory [1] gives closed-form expressions for the entanglement fidelities of the competing protocols and yields a sharp criterion for hybrid advantage. The experiment [2] combines logical DD with an error-detecting code to produce entangled logical states with fidelities exceeding those of the corresponding unprotected physical states.

[1] V. Kasatkin, A. Vezvaee, M. Morford-Oberst, D. Lidar, arXiv:2602.19042

2] A. Vezvaee, V. Tripathi, M. Morford-Oberst, F. Butt, V. Kasatkin, D. Lidar, Nature Comm. 17, 3281 (2026)