Impact of quantum coherence on the dynamics and thermodynamics of quenched free fermions coupled to a localized defect

• URL: http://arxiv.org/abs/2508.01444v1
• Date: Sat, 02 Aug 2025 17:21:19 GMT
• Title: Impact of quantum coherence on the dynamics and thermodynamics of quenched free fermions coupled to a localized defect
• Authors: Beatrice Donelli, Gabriele De Chiara, Francesco Scazza, Stefano Gherardini,
• Abstract summary: We investigate the non-equilibrium quantum dynamics and thermodynamics of free fermions suddenly coupled to a localized defect in a harmonic trap.<n>We show that initializing the system in a coherent superpositions of energy eigenstates leads to non-classical features.
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• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We investigate the non-equilibrium quantum dynamics and thermodynamics of free fermions suddenly coupled to a localized defect in a one-dimensional harmonic trap. This setup realizes a quantum quench transformation that gives rise to the orthogonalization of the system's wave-function as an effect of the localized perturbation. Using the Loschmidt echo and the Kirkwood-Dirac quasiprobability (KDQ) distribution of the work done by the defect, we quantify the extent and rate of the orthogonalization dynamics. In particular, we show that initializing the system in a coherent superpositions of energy eigenstates leads to non-classical features, such as Wigner function's negativity and non-positivity of the work KDQ distribution. Starting from simple single-particle superpositions and then progressing with coherent and cat states of few-body fermionic systems, we uncover how quantum coherence and few-body correlations shape the out-of-equilibrium response due to the presence of the defect.

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