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arXiv:2601.09792

Background cancellation for frequency-selective quantum sensing

Ricard Puig, Nathan Constantinides, Bharath Hebbe Madhusudhana, Daniel Bowring, C. Huerta Alderete, Andrew T. Sornborger

quant-phhep-thSubmitted Jan 14, 2026• Announced Jan 16, 2026• 0 citations
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Abstract

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.

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5 + 11 pages, 3 figures

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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.
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Abstract The field of quantum control and sensing encounters challenges due to various forms of time-dependent noise. We introduce a generalized filter-function framework that treats noise coupling strength as a tunable control parameter, enabling target noise suppression across user-defined frequency bands. By optimizing this generalized filter function, we design band-selective control pulses that achieve high fidelity of single- and two-qubit gates under strong noise with diverse spectral profiles. We further extend the method to selectively enhance the signal-to-noise ratio for quantum sensing of AC signals with an enhanced precision of up to 12.58 dB. The resulting control pulses are experimentally feasible, offering a practical pathway toward robust quantum operations and high-precision sensing under spectrally complex noises.
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