96 citations · 249 across the 9 of their papers we have counts for
9 papers
Coherence-induced quantum forces
Tarek A. Elsayed
We introduce a model that explains the phenomenon of correlation-assisted tunneling and puts it in a broader context. This model assumes the existence of an effective force of pure…
Effectiveness of classical spin simulations for describing NMR relaxation of quantum spins
Tarek A. Elsayed, Boris V. Fine
We investigate the limits of effectiveness of classical spin simulations for predicting free induction decays (FIDs) measured by solid-state nuclear magnetic resonance (NMR) on sys…
Sensitivity to small perturbations in systems of large quantum spins
Tarek A. Elsayed, Boris V. Fine
We investigate the sensitivity of nonintegrable large-spin quantum lattices to small perturbations with a particular focus on the time reversal experiments known in statistical phy…
Absence of exponential sensitivity to small perturbations in nonintegrable systems of spins 1/2
Boris V. Fine, Tarek A. Elsayed, Chahan M. Kropf +1
We show that macroscopic nonintegrable lattices of spins 1/2, which are often considered to be chaotic, do not exhibit the basic property of classical chaotic systems, namely, expo…
A Generalization of Fermat's Principle for Classical and Quantum Systems
Tarek A. Elsayed
The analogy between dynamics and optics had a great influence on the development of the foundations of classical and quantum mechanics. We take this analogy one step further and in…
Regression relation for pure quantum states and its implications for efficient computing
Tarek A. Elsayed, Boris V. Fine
We obtain a modified version of the Onsager regression relation for the expectation values of quantum-mechanical operators in pure quantum states of isolated many-body quantum syst…
Asymptotic and intermediate long-time behavior of nuclear free induction decays in polycrystalline solids and powders
Boris V. Fine, Tarek A. Elsayed, Eric G. Sorte +1
Free induction decay (FID) measured by nuclear magnetic resonance (NMR) in a polycrystalline solid is the isotropic average of the FIDs for individual single crystallites. It has b…
Signatures of Chaos in Time Series Generated by Many-Spin Systems at High Temperatures
Tarek A. Elsayed, Benjamin Hess, Boris V. Fine
Extracting reliable indicators of chaos from a single experimental time series is a challenging task, in particular, for systems with many degrees of freedom. The techniques availa…
Interpreting Recoil For Undergraduate Students
Tarek A. Elsayed
In this paper, I outline some problems in the students' understanding of the explanation of recoil motion when introduced to them in the context of Newton's third law. I propose to…