论文标题
SR $ _3 $ PBO ANTIPEROVSKITE的三维狄拉克电子的巨型轨道磁磁性
Giant orbital diamagnetism of three-dimensional Dirac electrons in Sr$ _3$PbO antiperovskite
论文作者
论文摘要
在狄拉克半法中，当费米水平接近狄拉克点时，理论上已经知道了带间混合，从而引起巨大的轨道diamagnetism。在bi $ _ {1-x} $ sb $ _x $和其他狄拉克半仪器中，已经观察到并将其解释为磁化易感性$χ$中的增强型diamagnetism，并将其解释为这种巨型轨道疾病的体现。但是，在实验上证明其轨道起源仍然具有挑战性。立方Antiperovskite Sr $ _3 $ PBO是一个三维狄拉克电子系统，如其他Dirac半决赛中显示了$χ$的巨型Diamagnetism。 $ ^{207} $ pb NMR测量在本研究中进行了探索diamagnetism的微观起源。从对$χ$的骑士移位$ k $的分析以及放松率$ t_1^{ - 1} $对于具有不同孔密度的样品的$ t_1^{ - 1} $，$ k $中的旋转和轨道成分已成功分开。结果表明，SR $ _3 $ PBO中增强的Diamagnetism源自Dirac电子的轨道贡献，这完全与巨型轨道轨道diamagnetism的理论完全一致。
In Dirac semimetals, inter-band mixing has been known theoretically to give rise to a giant orbital diamagnetism when the Fermi level is close to the Dirac point. In Bi$ _{1-x}$Sb$ _x$ 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. Cubic antiperovskite Sr$ _3$PbO is a three-dimensional Dirac electron system and shows the giant diamagnetism in $χ$ as in the other Dirac semimetals. $ ^{207}$Pb 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 $T_1^{-1}$ 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 Sr$ _3$PbO originates from the orbital contribution of Dirac electrons, which is fully consistent with the theory of giant orbital diamagnetism.
