Fault-tolerant quantum computing is often framed as an exercise in adding physical qubits until logical error rates become sufficiently low. We pursue a complementary approach: exploiting the large Hilbert space of superconducting microwave cavities to implement bosonic codes, embedding quantum error correction directly into the physical structure of each logical qubit and reducing hardware overhead.



In this talk, we will present recent experimental and engineering progress toward scaling this architecture from individual error-corrected qubits to increasingly integrated multi-qubit systems. We will highlight advances in logical-qubit preparation, measurement, control, error correction, and multi-qubit operations, together with progress toward larger hardware implementations. We will also discuss the role of adaptive measurement, feedback, and control in improving the robustness and performance of bosonic quantum operations.



Together, these developments illustrate the continued maturation of a hardware-efficient approach to fault-tolerant quantum computing. We will discuss how bosonic encoding provides complementary scaling axes and how progress at the level of logical-qubit performance, control, and system scale can combine into a practical path toward larger fault-tolerant quantum systems.