Long-time storage of entangled logical states in decoherence-free subspaces

• URL: http://arxiv.org/abs/2603.07190v1
• Date: Sat, 07 Mar 2026 13:01:25 GMT
• Title: Long-time storage of entangled logical states in decoherence-free subspaces
• Abstract summary: Maintenance of quantum entanglement lays the elementary building block of quantum information processing.<n>We encode two-qubit entangled states into the decoherence-free subspaces of four ions in a cryogenic trap.<n>We achieve a storage lifetime of about one hour for the entangled logical states.
• Score: 0.5365203575002531
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: The maintenance of quantum entanglement lays the elementary building block of quantum information processing, requiring an integration of long coherence time, sufficient storage capacity, and high-fidelity entangling gates. Here we encode two-qubit entangled states into the decoherence-free subspaces (DFS) of four ions in a cryogenic trap. By crosstalk-free sympathetic cooling under dual-type encoding and multi-state detection which discards the collision-induced leakage error, we achieve a storage lifetime of about one hour for the entangled logical states. We further study the second-order DFS and show its advantage in suppressing the spatially nonuniform noise over the first-order DFS. Our work paves the way for applications of DFS quantum memories in quantum computing, quantum network and precision measurement.

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