We consider the Cauchy problem for the massive Dirac equation in the non-extreme Kerr-Newman geometry outside the event horizon. We derive an integral representation for the Dirac propagator involving the solutions of the ODEs which arise in Chandrasekhar’s separation of variables. It is proved that for initial data in L∞ loc near the event horizon with L decay at infinity, the probability of t...

Recently three-dimensional topological quantum materials with gapless energy spectra have attracted considerable interest in many branches of physics. Besides the celebrated example, Dirac and Weyl points which possess gapless point structures in the underlying energy dispersion, the topologically protected gapless spectrum, can also occur along a ring, named Dirac and Weyl nodal rings. Ultraco...

The author’s idea of algebraic compositeness of fundamental particles, allowing to understand the existence in Nature of three fermion generations, is revisited. It is based on two postulates. (i) For all fundamental particles of matter the Dirac square-root procedure √ p2→Γ · p works, leading to a sequence N = 1, 2, 3, . . . of Dirac-type equations, where four Dirac-type matrices Γ μ are embed...

Based on the first principles calculation, we investigate the electronic band structures of graphene-MoS2 and Ti-MoS2 heterojunctions under gate-voltages. By simultaneous control of external electric fields and carrier charging concentrations, we show that the graphene's Dirac point position inside the MoS2 bandgap is easily modulated with respect to the co-varying Fermi level, while keeping th...

A fully relativistic time-dependent close-coupling method is developed based on Dirac’s covariant formulation of quantum mechanics. The expansion of a one-electron wave function in spin-orbit eigenfunctions yields the well-known coupled Dirac equations in two radial wave functions, while the expansion of a twoelectron wave function in coupled spin-orbit eigenfunctions yields close-coupled Dirac...

We solve the Dirac–Bogoliubov–de Gennes equation in an impurity-free superconductor–normal-metal– superconductor junction, to determine the maximal supercurrent Ic that can flow through an undoped strip of graphene with heavily doped superconducting electrodes. The result Ic W /L e 0 / is determined by the superconducting gap 0 and by the aspect ratio of the junction length L small relative to ...

The change in resistance of a material in a magnetic field reflects its electronic state. In metals with weakly- or non-interacting electrons, the resistance typically increases upon the application of a magnetic field. In contrast, negative magnetoresistance may appear under some circumstances, e.g., in metals with anisotropic Fermi surfaces or with spin-disorder scattering and semimetals with...

We discuss the ultrafast evolution of the surface electronic structure of the topological insulator Bi(2)Te(3) following a femtosecond laser excitation. Using time and angle-resolved photoelectron spectroscopy, we provide a direct real-time visualization of the transient carrier population of both the surface states and the bulk conduction band. We find that the thermalization of the surface st...

Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi2Te3 with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be ...