Quantum error correction with loss in hybrid photonic–atomic architectures

To achieve a practically viable error rate, a universal quantum computer must encode a large number of imperfect physical qubits into an appropriate error-correcting code, hosting logical qubits.  Realizing such large codes in hardware is challenging, as it demands both a high density of controllable qubits and the ability to generate entanglement at scale. In this respect, photonic platforms are especially attractive - photons act as flexible carriers of entanglement, while atoms provide long-lived, controllable memories. However, this division of roles makes the architecture highly sensitive to photon loss. 

In my talk, I will discuss how loss in the photonic subsystem propagates into the atomic layer, effectively turning photon-loss events into errors on the atomic qubits. I will show how we address this problem using a loss-aware decoder tailored to this hybrid setting, and compare its performance to exact quantum simulations of the underlying dynamics.