Fast control of bosonic modes using driven qubtis

One of the central challenges in quantum computing is to reconcile two conflicting goals: protecting quantum states from their environment while still being able to control them quickly. Bosonic modes in superconducting circuits are a striking example. They offer long-lived quantum memories, but their very coherence can make initialization, manipulation, and coupling slow and difficult. In this colloquium I will show how driven ancilla qubits provide a way around this trade-off. After introducing the broader idea of fast control in weakly coupled bosonic hardware, I will present two recent experiments from our group: rapid reset of a high-Q cavity through engineered dissipation, and fast coherent operations enabling Fock-state preparation, photon transfer between long-lived modes, and Bell-state generation. These advances illustrate a broader route toward quantum hardware that is both robust and controllable.