Smith, Charles E.2017-09-202017-09-202016-05-12Smith, C.E. Comparing the Models of Steepest Entropy Ascent Quantum Thermodynamics, Master Equation and the Difference Equation for a Simple Quantum System Interacting with Reservoirs. Entropy 2016, 18, 176.http://hdl.handle.net/10919/79277There is increasing interest concerning the details about how quantum systems interact with their surroundings. A number of methodologies have been used to describe these interactions, including Master Equations (ME) based on a system-plus-reservoir (S + R) approach, and more recently, Steepest Entropy Ascent Quantum Thermodynamics (SEAQT) which asserts that entropy is a fundamental physical property and that isolated quantum systems that are not at stable equilibrium may spontaneously relax without environmental influences. In this paper, the ME, SEAQT approaches, and a simple linear difference equation (DE) model are compared with each other and experimental data in order to study the behavior of a single trapped ion as it interacts with one or more external heat reservoirs. The comparisons of the models present opportunities for additional study to verify the validity and limitations of these approaches.application/pdfenCreative Commons Attribution 4.0 Internationalquantum thermodynamicsquantum relaxationquantum entropySEAQTArticle - Refereed2017-09-20https://doi.org/10.3390/e18050176