Experimental demonstration of entanglement pumping with bosonic logical qubits

Entanglement is crucial for quantum networks and computation, yet maintaining high-fidelity entangled quantum states is hindered by decoherence and resource-intensive purification methods. Here, we experimentally demonstrate entanglement pumping, utilizing bosonic quantum error correction (QEC) codes as long-coherence-time storage qubits. By repetitively generating entanglement with short-coherence-time qubits and injecting it into QEC-protected logical qubits, our approach effectively preserves entanglement. Through error detection to discard error states and entanglement pumping to mitigate errors within the code space, we extend the lifespan of entangled logical qubits by nearly 50% compared to the case without entanglement pumping. This work highlights the potential of bosonic logical qubits for scalable quantum networks and introduces a novel paradigm for efficient entanglement management.