Giant orbital diamagnetism of three-dimensional Dirac electrons in Sr${}_3$PbO antiperovskite

Abstract

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 $\chi$ 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 $\chi$ 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 $\chi$ 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.

References in corpus (12)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Classification of stable three-dimensional Dirac semimetals with nontrivial topology
• Quantum transport evidence for a three-dimensional Dirac semimetal phase in Cd3As2
• Linear magnetoresistance caused by mobility fluctuations in the n-doped Cd3As2
• Topological Crystalline Insulators and Dirac Octets in Anti-perovskites
• Transport Properties and Diamagnetism of Dirac Electrons in Bismuth
• Orbital magnetism of coupled bands models
• Low-Energy Effective Hamiltonian and the Surface States of Ca_3PbO
• Thermodynamic signatures for the existence of Dirac electrons in ZrTe5
• Exotic Landau Diamagnetism and Weyl-Fermions Excitations in TaAs Revealed by ${}^{75}$As NMR and NQR
• Nuclear Spin Relaxation Time due to the Orbital Currents in Dirac Electron Systems

Cited by in corpus (9)

• Anomalous Spin Transport Properties of Gapped Dirac Electrons with Tilting
• Nonlinear and nonreciprocal transport effects in untwinned thin films of ferromagnetic Weyl metal SrRuO${}_3$
• Linear Magnetoresistance and Type-I Superconductivity in $\beta$-IrSn${}_4$
• Perspective: Molecular beam epitaxy of antiperovskite oxides
• Uniform electronic states and $s$-wave superconductivity in a strongly disordered high-entropy compound (RuRhPdIr)${}_{0.6}$Pt${}_{0.4}$Sb
• Site-dependent Local Spin Susceptibility and Low-energy Excitation in a Weyl Semimetal WTe${}_2$
• Disentangling Orbital Magnetic Susceptibility with Wannier Functions
• Robust orbital diamagnetism of correlated Dirac fermions in chiral Ising universality class
• Controlling Orbital Magnetism of Band Electron Systems via Bath Engineering