Erasure-detected quantum operations between bosonic qubits encoded in superconducting cavities

Superconducting microwave cavities have emerged as promising platforms for quantum memories, achieving single-photon coherence times on the order of tens of milliseconds [1]. However, leveraging these long photon lifetimes to realize high-fidelity two-qubit gates is limited by the noisy, non-linear ancilla qubit used to control the cavities. Detecting and converting dominant ancilla errors into erasures can improve the post-selected gate fidelity and significantly benefit quantum error correction codes.

In this talk, we present our results toward realizing erasure-detected quantum operations between bosonic qubits encoded in superconducting cavities. We use a novel ancilla qubit for controlling the cavity, allowing the conversion of dominant ancilla errors into detectable erasures. Combined with the ancilla's suppressed residual decoherence, our approach shows significant promise for realizing high-fidelity quantum gates on cavity qubits.

[1] Milul, Guttel et al., PRX Quantum 4, 030336, 2023