Giant orbital diamagnetism of three-dimensional Dirac electrons in Sr3PbO antiperovskite

Autor: H. Takagi, Toshikaze Kariyado, Juergen Nuss, Andreas W. Rost, S. Suetsugu, Kentaro Kitagawa, Claus Mühle, Masao Ogata
Přispěvatelé: University of St Andrews. School of Physics and Astronomy, University of St Andrews. Centre for Designer Quantum Materials
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Popis: This work was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI (Grants No. 24224010, No. 15K13523, No. JP15H05852, No. JP15K21717,, No. 17H01140, No. 18H01162, and No. 17J05243), JSPS Core-to-Core Program (A) Advanced Research Networks, and the Alexander von Humboldt Foundation. S.S. acknowledges financial support by JSPS and the Materials Education program for the future leaders in Research, Industry, and Technology (MERIT). 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−xSbx and other Dirac semimetals, an enhanced diamagnetism in the magnetic susceptibility χ 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 Sr3PbO is a three-dimensional Dirac electron system and shows the giant diamagnetism in χ as in the other Dirac semimetals. 207Pb NMR measurements are conducted in this study to explore the microscopic origin of diamagnetism. From the analysis of the Knight shift K as a function of χ and the relaxation rate T1–1 for samples with different hole densities, the spin and the orbital components in K are successfully separated. The results establish that the enhanced diamagnetism in Sr3PbO originates from the orbital contribution of Dirac electrons, which is fully consistent with the theory of giant orbital diamagnetism. Publisher PDF
Databáze: OpenAIRE