Tohoku University “found the Dirac electron effective mass zero at an atomic layer iron-based high-temperature superconductors!”

【Overview】 Ko Nakayama 輔助 Professor of Tohoku University Graduate School of Science, adjuvants Fujiyu history professor, research group of Takahashi, Takashi professors of the University Materials Science Institute of Advanced Studies, in the atomic layer iron-based high-temperature superconductors, with the nature of the mass zero " we found the Dirac electrons (Note 1) ". This achievement, not only pave the way to the realization of ultra-high-speed, super-conducting nano-devices, will also be an important step towards the elucidation of the expression mechanism of high temperature superconductivity. This result is selected to the attention thesis of the American Physical Society journal Physical Review · B, was published in the online preliminary version in 2017 December 29, (US Eastern Time). [Contents of the study] This research group of Tohoku University, using the molecular beam epitaxy method (Note 4) was prepared FeSe thin high quality one layer is controlled at the atomic level on a substrate of oxide. Further, a thin film formed by heating under a precise temperature control in a ultra-high vacuum, thin film high-temperature superconductivity occurs in the case of high-temperature heating, in the case of low temperature heating and a thin film superconducting does not occur at all in nature It was the first to successfully be divided to create a different FeSe atomic layer thin film. As an electron state angle resolved photoemission spectroscopy of the thin film (note 5) results were examined using a technique called (Fig. 2), a thin film that does not exhibit superconductivity obtained by low-temperature heating, that there is Dirac electron massless the was revealed. Further, as a result of similar measurement for the multi-layered film of 2 to 20 layers, ideal Dirac electron system only Dirac electrons responsible for conduction, we discovered that it is realized only by atomic layer thin film of one layer It was. In other words, the realization of the ideal Dirac electron system is, it says that the nature of the atomic layer thin film unique. The present study, FeSe atomic layer thin film is not high-temperature superconductor only, it was found that also has properties as a Dirac electron system similar to graphene. In addition, these two completely different properties of, we also found that to be switched in a very simple method of changing the heating temperature. ※ the link below, some excerpts. Following is a source https://mainichi.jp/articles/20180112/pls/00m/020/501000c (;'Д `) but neat but now can run at 45 minutes 10km when I was running every day Noriko-chan "The Japanese became that result from the vote according to the prediction of amenable. Media of victory New Komeito to predict!" Dog "Let's go more" me "No go home again" → 15 years after the www Matter Wai is somehow suspected from whistleblowers the criminal and the company wwww Customer "wonder if this job was difficult in your company! Ha ha ha!" Business Wye "... Dekiraa'!" Technical Department "What?"
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