Milul O., Guttel B., Goldblatt U., Hazanov S., Joshi L. M., Chausovsky D., Kahn N., Çiftyürek E., Lafont F. & Rosenblum S.
(2023)
PRX Quantum.
4,
3,
030336.
Storing quantum information for an extended period of time is essential for running quantum algorithms with low errors. Currently, superconducting quantum memories have coherence times of a few milliseconds, and surpassing this performance has remained an outstanding challenge. In this work, we report a single-photon qubit encoded in a novel superconducting cavity with a coherence time of 34 ms, representing an order of magnitude improvement compared to previous demonstrations. We use this long-lived quantum memory to store a Schrödinger cat state with a record size of 1024 photons, indicating the cavity's potential for bosonic quantum error correction.