Narrow Results

Recently, electron vortices have attracted attention both experimentally and theoretically. A study on the Landau–Dirac problem is made to understand the nature of electron vortices. This line of investigation is motivated by the recent literature on the Landau problem that throws new insights on the nature of orbital angular momentum, i.e. canonical versus kinetic in the context of QCD. The significance of pure gauge vector potential, nontrivial topology and exchange of modular orbital angular momentum to understand the physical origin of electron vortices in the Landau–Dirac problem are new contributions of this paper.

Isotropic oscillator and Coulomb problems are known to have interesting correspondence. We focus on two-dimensional (2D) quantum problems and present complete treatment on the correspondence including the Schrödinger equation, eigenfunctions and eigenvalues, and the integrals of motion. We find only partial equivalence. The wave function correspondence is examined introducing local gauge transformation and the emergence of half-quantized vortex with the associated spin-half is established. Vortex structure of the electron proposed by us and the origin of charge are discussed in this paper. Outlook on the implications for QCD and hadron spectrum is outlined.

Role of gauge symmetry in the proton spin problem has intricate and unresolved aspects. One of the interesting approaches to gain physical insights is to explore the Landau problem in this context. A detailed study using the group theoretic method to understand the Landau problem establishes the significance of the gauge transformation intimately related with the space translation symmetry. An important implication of this result is that the E(2)-like Wigner’s little group for massless particles could throw more light on the question of gauge symmetry in QED and QCD. A generalized Landau-Zeeman Hamiltonian is proposed in which Dirac two-oscillator system and the symmetry of the group SO(3,2) become important. It is argued that nontrivial topology of pure gauge field holds promise to resolve the unsettled questions.