Positive Hamiltonians cannot give exponential decay of positive observables

Facchi P, Lonigro D (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Journal of Physics A: Mathematical and Theoretical Institute of Physics Publishing (IOP)

Book Volume: 57

Article Number: 015302

Journal Issue: 1

DOI: 10.1088/1751-8121/ad0f48

Abstract

The survival probability of a quantum system with a finite ground energy is known to decay subexponentially at large times. Here we show that, under the same assumption, the average value of any quantum observable, whenever well-defined, cannot converge exponentially to an extremal value of the spectrum of the observable. Large-time deviations from the exponential decay are therefore a general feature of quantum systems. As a simple application of these results, we show that, when considering an open quantum system whose dynamics is generated by a Hamiltonian with a finite ground energy, a large-time exponential decay of populations is forbidden, whereas coherences may still decay exponentially.

Authors with CRIS profile

Davide Lonigro

Involved external institutions

University of Bari Aldo Moro / Università degli Studi di Bari Aldo Moro IT Italy (IT)

How to cite

APA:

Facchi, P., & Lonigro, D. (2024). Positive Hamiltonians cannot give exponential decay of positive observables. Journal of Physics A: Mathematical and Theoretical, 57(1). https://doi.org/10.1088/1751-8121/ad0f48

MLA:

Facchi, Paolo, and Davide Lonigro. "Positive Hamiltonians cannot give exponential decay of positive observables." Journal of Physics A: Mathematical and Theoretical 57.1 (2024).

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