{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,18]],"date-time":"2026-04-18T00:52:22Z","timestamp":1776473542197,"version":"3.51.2"},"reference-count":43,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,7,28]],"date-time":"2025-07-28T00:00:00Z","timestamp":1753660800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000925","name":"John Templeton Foundation","doi-asserted-by":"publisher","award":["62422"],"award-info":[{"award-number":["62422"]}],"id":[{"id":"10.13039\/100000925","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Endoreversible engine cycles are a cornerstone of finite-time thermodynamics. We show that endoreversible Stirling engines operating with a one-component plasma as a working medium run at maximal power output with the Curzon\u2013Ahlborn efficiency. As a main result, we elucidate that this is actually a consequence of the fact that the caloric equation of state depends only linearly on temperature and only additively on volume. In particular, neither the exact form of the mechanical equation of state nor the full fundamental relation are required. Thus, our findings immediately generalize to a larger class of working plasmas, far beyond simple ideal gases. In addition, we show that for plasmas described by the photonic equation of state, the efficiency is significantly lower. This is in stark contrast to endoreversible Otto cycles, for which photonic engines have an efficiency larger than the Curzon\u2013Ahlborn efficiency.<\/jats:p>","DOI":"10.3390\/e27080807","type":"journal-article","created":{"date-parts":[[2025,7,28]],"date-time":"2025-07-28T14:50:03Z","timestamp":1753714203000},"page":"807","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Endoreversible Stirling Cycles: Plasma Engines at Maximal Power"],"prefix":"10.3390","volume":"27","author":[{"given":"Gregory","family":"Behrendt","sequence":"first","affiliation":[{"name":"Department of Physics, University of Maryland, Baltimore County, Baltimore, MD 21250, USA"},{"name":"Quantum Science Institute, University of Maryland, Baltimore County, Baltimore, MD 21250, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0504-6932","authenticated-orcid":false,"given":"Sebastian","family":"Deffner","sequence":"additional","affiliation":[{"name":"Department of Physics, University of Maryland, Baltimore County, Baltimore, MD 21250, USA"},{"name":"Quantum Science Institute, University of Maryland, Baltimore County, Baltimore, MD 21250, USA"},{"name":"National Quantum Laboratory, College Park, MD 20740, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Conde, L. 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