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arXiv · 2610.40612

Exceptional Points as Witnesses of Non-Gaussian Noise

Aritra Ghosh·Subhashish Banerjee·M. Bhattacharya
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Abstract

Efficient control of quantum devices requires the knowledge of their environmental noise, yet the commonly measured power spectrum does not fully characterize non-Gaussian fluctuations of realistic environments. Here we show that exceptional points (EPs) in the noise-averaged dephasing response can expose observable signatures of non-Gaussian statistics, distinguishing environments with identical lower-order statistics. We also introduce a theoretical model that describes dephasing environments in terms of identical independent noise sources while preserving the power spectrum. Given a calibrated single-source model, the largest EP order extracted from the measured dephasing response determines the number of sources and predicts the higher-order statistics of the combined noise. We illustrate an atomtronic readout that maps distinct EP signatures onto an evolving ensemble-averaged atomic interference pattern. Our results connect non-Hermitian dynamics to environmental noise statistics, providing a route to characterize noise in quantum devices used in computing, metrology, and precision measurement.

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Aritra Ghosh, Subhashish Banerjee, M. Bhattacharya. 2026-10-29. Exceptional Points as Witnesses of Non-Gaussian Noise. https://arxiv.org/abs/2610.40612

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