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arXiv · 2608.06562

Detecting quantumness with generalized Loschmidt echoes

Cecilia Cormick·Adrián A. Budini
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Abstract

Loschmidt echoes are a well-established method to characterize dynamical properties such as quantum chaos and sensitivity to perturbations. Here we present a straightforward generalization that identifies non-classical dynamical behavior. The generalized echoes involve four forward-backward time propagators. If these propagators do not commute, one can readily identify signatures of this property in the relations between echoes. As an example, detection of intrinsic non-commuting quantum features is analyzed in critical dynamics of a spin chain. Interestingly, this phenomenon is also observed for Gaussian dynamics and high temperature limits which are generally regarded as classical.

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Cecilia Cormick, Adrián A. Budini. 2026-08-06. Detecting quantumness with generalized Loschmidt echoes. https://doi.org/10.1016/j.physleta.2026.132011

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