{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:44:24Z","timestamp":1760233464797,"version":"build-2065373602"},"reference-count":35,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,1,20]],"date-time":"2021-01-20T00:00:00Z","timestamp":1611100800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002241","name":"Japan Science and Technology Agency","doi-asserted-by":"publisher","award":["JPMJCR18T1"],"award-info":[{"award-number":["JPMJCR18T1"]}],"id":[{"id":"10.13039\/501100002241","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["JP17H04847","JP17H01139","JP18H01160","JP20H01847"],"award-info":[{"award-number":["JP17H04847","JP17H01139","JP18H01160","JP20H01847"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>The discovery of high-temperature (high-Tc) superconductivity in one-monolayer FeSe on SrTiO3 has attracted tremendous attention. Subsequent studies suggested the importance of cooperation between intra-FeSe-layer and interfacial interactions to enhance Tc. However, the nature of intra-FeSe-layer interactions, which would play a primary role in determining the pairing symmetry, remains unclear. Here we have performed high-resolution angle-resolved photoemission spectroscopy of one-monolayer and alkaline-metal-deposited multilayer FeSe films on SrTiO3, and determined the evolution of quasiparticle band dispersion across Tc. We found that the band dispersion in the superconducting state deviates from the Bogoliubov-quasiparticle dispersion expected from the normal-state band dispersion with a constant gap size. This suggests highly anisotropic pairing originating from small momentum transfer and\/or mass renormalization due to electron\u2013boson coupling. This band anomaly is interpreted in terms of the electronic interactions within the FeSe layers that may be related to the high-Tc superconductivity in electron-doped FeSe.<\/jats:p>","DOI":"10.3390\/sym13020155","type":"journal-article","created":{"date-parts":[[2021,1,21]],"date-time":"2021-01-21T02:36:05Z","timestamp":1611196565000},"page":"155","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Unusual Temperature Evolution of Quasiparticle Band Dispersion in Electron-Doped FeSe Films"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2462-2253","authenticated-orcid":false,"given":"Kosuke","family":"Nakayama","sequence":"first","affiliation":[{"name":"Department of Physics, Tohoku University, Sendai 980-8578, Japan"},{"name":"Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Tokyo 102-0076, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Koshin","family":"Shigekawa","sequence":"additional","affiliation":[{"name":"Department of Physics, Tohoku University, Sendai 980-8578, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katsuaki","family":"Sugawara","sequence":"additional","affiliation":[{"name":"Department of Physics, Tohoku University, Sendai 980-8578, Japan"},{"name":"Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Tokyo 102-0076, Japan"},{"name":"WPI Research Center, Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan"},{"name":"Center for Spintronics Research Network, Tohoku University, Sendai 980-8577, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takashi","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Department of Physics, Tohoku University, Sendai 980-8578, Japan"},{"name":"WPI Research Center, Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan"},{"name":"Center for Spintronics Research Network, Tohoku University, Sendai 980-8577, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takafumi","family":"Sato","sequence":"additional","affiliation":[{"name":"Department of Physics, Tohoku University, Sendai 980-8578, Japan"},{"name":"WPI Research Center, Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan"},{"name":"Center for Spintronics Research Network, Tohoku University, Sendai 980-8577, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"14262","DOI":"10.1073\/pnas.0807325105","article-title":"Superconductivity in the PbO-type structure \u03b1-FeSe","volume":"105","author":"Hsu","year":"2009","journal-title":"Proc. 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