A key challenge in quantum sensing is the detection of weak time dependent signals, particularly those that arise as specific frequency perturbations over a background field. Conventional methods usually demand complex dynamical control of the quantum sensor and heavy classical post-processing. We propose a quantum sensor that leverages time independent interactions and entanglement to function as a passive, tunable, thresholded frequency filter. By encoding the frequency selectivity and thresholding behavior directly into the dynamics, the sensor is responsive only to a target frequency of choice whose amplitude is above a threshold. This approach circumvents the need for complex control schemes and reduces the post-processing overhead.
@article{arxiv.2601.09792,
title = {Background cancellation for frequency-selective quantum sensing},
author = {Ricard Puig and Nathan Constantinides and Bharath Hebbe Madhusudhana and Daniel Bowring and C. Huerta Alderete and Andrew T. Sornborger},
journal= {arXiv preprint arXiv:2601.09792},
year = {2026}
}