Quantum-Network Nodes with Real-Time Noise Mitigation Using Spectator Qubits
Year: 2026
Type: article
Abstract: Quantum networks might enable quantum communication and distributed quantum computation. Solid-state defects are promising platforms for such networks, because they provide an optical interface for remote entanglement distribution and a nuclear-spin register to store and process quantum information. A key challenge toward larger networks is to improve the storage of previously generated entangled states during new entanglement generation. Here, we introduce a method that uses “spectator” qubits combined with real-time decision making and feedforward to mitigate dephasing of stored quantum states during remote entanglement sequences. We implement the protocol using a single nitrogen-vacancy (NV) center in diamond and demonstrate improved memory fidelity. Our results show that spectator qubits can improve quantum network memory using minimal overhead and naturally present resources, making them a promising addition for near-term testbeds for quantum networks.
Source: PRX Quantum
DOI: 10.1103/zgm8-6b8l
Authors: S.J.H. Loenen, Y. Wang, N. Demetriou, C.E. Bradley, T.H. Taminiau
Institutions: QuTech, Delft University of Technology, University of Stuttgart
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,450
Awards: G1665575404, G22081376, Fault-tolerant protection of quantum states with spins in diamond, A quantum network for distributed quantum computation, G490769153, Verbundprojekt: Quantenfehlerkorrektur für vernetzte hybride Quantengeräte - QECHQS -, Teilvorhaben: Quantenfehlerkorrektur für Spin-Phonon-Photonen-Schnittstellen - QECSPP
OpenAlex ID: W4417084782