Real-time magnetic field noise correction using trapped-ion monitor qubits

2025/11/06 by DeBry, Kyle, Valdes-Martinez, Agustin, Reens, David +2 · 1 citation
Computer Science · Physics and Astronomy · #Atomic Physics (physics.atom-ph) #Atomic and Subatomic Physics Research #FOS: Physical sciences #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum optics and atomic interactions

paper · doi:10.48550/arxiv.2511.04767

openalex publication_date 2025/11/06 · openalex created_date 2025/11/11 · openalex updated_date 2026/07/28

Abstract

We demonstrate a trapped-ion protocol in which a nearby, dedicated "monitor" qubit tracks magnetic-field drifts in real time without interrupting data-qubit operations. Using two ⁴⁰Ca⁺ ions and the optical--metastable--ground architecture, we encode the data qubit in the ground-state manifold and the monitor qubit in a metastable-state manifold to achieve spectral separation. The monitor qubit senses common magnetic fluctuations during data-qubit experiments, enabling feedforward corrections to the qubit-control drives. Under applied magnetic noise with a realistic spectrum (1/f²), the protocol maintains coherence and, when compared with interleaved calibration, it extends usable data-qubit probe times by up to a factor of ∼√(2) and doubles the experimental duty cycle. These results establish monitor qubits as a scalable tool for real-time recalibration in quantum information processors.

Citations

• Landé g factor measurement of ⁴⁸Ti⁺ using simultaneous co-magnetometry and quantum logic spectroscopy
• Quantum-network nodes with real-time noise mitigation using spectator qubits
• Excited-state magnetic properties of carbon-like Ca¹⁴⁺
• Imperfection analyses for random-telegraph-noise mitigation using spectator qubits
• A simple magnetic field stabilization technique for atomic Bose-Einstein condensate experiments
• Scalable, high-fidelity all-electronic control of trapped-ion qubits
• ArXiv

Cited by

• Fast-feedback protocols for calibration and drift control in quantum computers

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