{"id":2801,"date":"2021-04-23T18:21:32","date_gmt":"2021-04-23T09:21:32","guid":{"rendered":"https:\/\/www.phys.s.u-tokyo.ac.jp\/en\/?p=2801"},"modified":"2021-04-23T18:34:58","modified_gmt":"2021-04-23T09:34:58","slug":"giant-orbital-diamagnetism-of-three-dimensional-dirac-electrons-in-sr3pbo-antiperovskite","status":"publish","type":"post","link":"https:\/\/www.phys.s.u-tokyo.ac.jp\/en\/news\/2801\/","title":{"rendered":"Giant orbital diamagnetism of three-dimensional Dirac electrons in Sr3PbO antiperovskite"},"content":{"rendered":"\n
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In Dirac semimetals, interband mixing has been known theoretically to give rise to a giant orbital diamagnetism when the Fermi level is close to the Dirac point. In Bi1\u2212x<\/sub>Sbx<\/sub> and other Dirac semimetals, an enhanced diamagnetism in the magnetic susceptibility \u03c7<\/em> has been observed and interpreted as a manifestation of such giant orbital diamagnetism. Experimentally proving their orbital origin, however, has remained challenging. The cubic antiperovskite Sr3<\/sub>PbO is a three-dimensional Dirac electron system and shows the giant diamagnetism in \u03c7<\/em> as in the other Dirac semimetals. 207<\/sup>Pb NMR measurements are conducted in this study to explore the microscopic origin of diamagnetism. From the analysis of the Knight shift K<\/em> as a function of \u03c7 <\/em> and the relaxation rate T1<\/sub>\u20131<\/sup><\/em> for samples with different hole densities, the spin and the orbital components in K<\/em> are successfully separated. The results establish that the enhanced diamagnetism in Sr3<\/sub>PbO originates from the orbital contribution of Dirac electrons, which is fully consistent with the theory of giant orbital diamagnetism.<\/p>\n\n\n\n

See below for more information.<\/p>\n\n\n\n