Theory and Experimental Demonstration of Quantum Invariant Filtering
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.
Keywords
Cite
@article{arxiv.2506.15805,
title = {Theory and Experimental Demonstration of Quantum Invariant Filtering},
author = {Loris Maria Cangemi and Yoav Woldiger and Amikam Levy and Assaf Hamo},
journal= {arXiv preprint arXiv:2506.15805},
year = {2025}
}