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arXiv · 2506.15805

Theory and Experimental Demonstration of Quantum Invariant Filtering

Loris Maria Cangemi·Yoav Woldiger·Amikam Levy·Assaf Hamo
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Abstract

Quantum control protocols are typically devised in the time domain, leaving their spectral behavior to emerge only a posteriori. Here, we invert this paradigm. Starting from a target frequency-domain filter, we employ the dynamical-invariant framework to derive the continuous driving fields that enact the chosen spectral response on a qubit. This approach, Quantum Invariant Filtering (QIF), maps arbitrary finite-impulse responses, including multi-band and phase-sensitive profiles, into experimentally feasible Hamiltonian modulations. Implemented on a single nitrogen-vacancy center in diamond, the method realizes the prescribed passbands with high fidelity, suppresses noise, and preserves coherence for milliseconds, two orders of magnitude longer than Carr-Purcell-Meiboom-Gill sequences, while remaining robust to 50% drive-amplitude errors. Our results establish QIF as a broadly applicable framework for enhanced quantum control and sensing across diverse physical platforms, including superconducting qubits, trapped ions, and nuclear magnetic resonance systems.

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Loris Maria Cangemi, Yoav Woldiger, Amikam Levy, Assaf Hamo. 2025-06-18. Theory and Experimental Demonstration of Quantum Invariant Filtering. https://arxiv.org/abs/2506.15805

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